LITERATURE REVIEW

INTRODUCTION

Our focus in this chapter is to critically examine relevant literatures that would assist in explaining the research problem and furthermore recognize the efforts of scholars who had previously contributed immensely to similar research. The chapter intends to deepen the understanding of the study and close the perceived gaps.

Precisely, the chapter will be considered in two sub-headings:

Conceptual Framework

Chapter Summary

2.1 CONCEPTUAL FRAMEWORK

HIV Prevalence

More than 33.2 million people are living with HIV throughout the world. The greatest burden of the disease is concentrated in developing countries, the least able to cope. In these regions,HIV/AIDS has deepened poverty and exacerbated food insecurity (UNAIDS & WHO 2009).HIV/AIDS and malnutrition effects are interrelated and exacerbate one another in a vicious cycle. HIV specifically affects nutritional status by increasing energy requirements, reducing food intake, and adversely affecting nutrient absorption and metabolism. Asymptomatic and symptomatic adults have energy requirements by 10% and 30% respectively to maintain body weight and physical activity (Steinhart, 2011). HIV prevalence was higher in the urban location(5.7%) than rural (3.7%) areas except in the Southeast zone of Nigeria (FMOH, 2008). The difference was more pronounced in the Southwest and Northeast. Generally, about 65% of all new adults HIV infections occur in young men and women of less than 30years old, (FMOH,2008). The human immune-deficiency virus (HIV) targets the immune system, making an infected person susceptible to infections and neoplasm because of an impaired ability to mount an adequate immune response. Malnutrition and its‘ complication have been largely found to render HIV infected persons susceptible to opportunistic infection and reduce effectiveness and tolerance to medication and other therapies, (Castlemanet al.,2004). Nutritional status is easily compromised during any type of infection. Generalized infections often result in low intake and absorption of nutrients, (Friis,2006). Inadequate nutrient intake or disturbance in the body‘s ability to process nutrients can result in lean body mass and wasting (Kotler,2000). Death occurs when a person‘s weight reaches about 60% of his/her ideal body weight regardless of the cause, (Kotler,2000).Evidence has shown that adequate nutrition for a person living HIV(PLHIV) is necessary to maintain and improve the overall health and nutritional status.

Promising developments have been seen in recent years in global efforts to address AIDS epidemic by increasing access to effective treatment and prevention programmes.

NUTRITIONAL STATUS

HIV and nutrition are interrelated and as antiretroviral drug become increasingly available in the poorest parts of the world, critical questions are emerging about how well the drugs work in people if they are short of food, and for those already receiving treatment, side effects such as body fat changes are a daily concern (Bartlett, 2003). Maintaining a good nutritional status is important to support the overall health and immune function of people living with HIV/AIDS(PLWHA). Adequate nutrition refers to intake of a diet which meets the specific nutritional needs for the specific individual for that specific period in time (Bartlett, 2003). The sole aim of adequate nutrition is to meet the growth and developmental demands of the unique, specific individuals‘ body (Walsh et al., 2003).Inadequate nutrition in people with HIV infection may result from many factors including nausea, vomiting and anorexia that may prevent adequate intake of nutrients and medications; diarrheal infections that prevent absorption of nutrients and medications; Oral health conditions that interfere with chewing or tasting food like Oral Candidiasis in patients who present late;systemic illness (including HIV itself) that create a catabolic state; and psychological conditions such as depression that impair patients‘ ability to nourish themselves (Bartlett, 2003; Steinhart, 2011). In addition, financial constraints may limit patients‘ access to nutritious food(Walsh et al., 2003). Adequate nutrition helps to maintain and improve the nutritional and immunological status of a person with HIV/AIDS and delay the progression from HIV to AIDS-related diseases (Walsh et al., 2003). It can therefore improve the quality of life of PLWHA. Adequate nutrition will complement the effects of antiretroviral therapies and will help to maintain body weight and fitness, as well as improve the performance of the immune system already compromised by the infection (Walsh et al., 2003). Whereas starving people tend to lose fat first, the weight lost during HIV infection tends to be in the form of lean tissue such as muscle mass; this has been attributed to ARTs like Polymerase Inhibitors. This means there may be changes in the makeup of the body even if the overall weight stays the same(WHO, 2005; WHO, 2008). One factor behind HIV-related weight loss is increased energy expenditure (Newell etal., 2003; Batterham, 2005). Many studies indicate that people with HIV tend to burn around 10% more calories while resting, compared to those who are uninfected(WHO, 2005; Batterham, 2005). Studies point to low energy intake combined with increased energy demands due to HIV infection and related infections as the major driving forces behind HIV-related weight loss and wasting. Based on increased resting energy expenditure (REE)observed in studies of HIV-infected adults, it is recommended that energy be increased by 10%over accepted levels for otherwise healthy people. The goal is to maintain body weight in asymptomatic HIV-infected adults. Although studies of energy expenditure have not shown an increase in total energy expenditure (TEE), this may have been the result of individuals compensating by reducing activity-related energy expenditure (AEE). Since maintaining physical activity is highly desirable for preserving quality of life and maintaining muscle tissue,it is undesirable that energy intake should only match a reduced level of AEE. The estimated energy requirement therefore allows for normal AEE levels on top of an increased level of REE. Increased energy intake of about 20% to 30% is recommended for adults during periods of symptomatic disease or opportunistic infection to maintain body weight. This takes into account the increase in REE with HIV-related infections. However, such intakes may not be achievable during periods of acute infection or illness, and it has not been proven that such high intake levels can be safely achieved during such periods. Moreover, it is recognized that physical activity may be reduced during HIV-related infections and the recommended increased intake is based on the energy needed to support weight recovery during and after HIV related illnesses. Intakes should therefore be increased to the extent possible during the recovery phase, aiming for the maximum achievable up to 30% above normal intake during the acute phase.Current antiretroviral drug treatments control HIV infection and prevent severe wasting, as well as other AIDS – related conditions. Emaciated persons tend to regain weight once they begin antiretroviral therapy and stunted children experience catch-up growth (Newell etal., 2003);however the drugs do not eliminate wasting. In addition, some antiretroviral drugs have been linked to lipodystrophy, as well as lipid abnormalities by raising Low Density Lipoprotein(LDL) cholesterol, lowering High Density Lipoprotein (HDL) cholesterol and raising triglyceride levels in the blood. This may result in higher risks of heart disease, Cerebro-Vascular Accidents (CVA) and diabetes mellitus (De Wit,et al., 2008). One study in Malawi found that patients with mild malnutrition (a Body Mass Index (BMI) of 17.00 - 18.49 kg/m2)were twice likely to die in the first three months of treatment; and for those with severe malnutrition (BMI less than 16.00 kg/m2), the risk was six times greater than those of healthy body weight (BMI ranging between 18.5 - 24.99 kg/m2) (WHO, 2005).Since the beginning of the pandemic, over 30 million people have died from AIDS-related causes globally (Victoria et al., 2009). In Nigeria, an estimated 4.6% of the populations are living with HIV/AIDS (Hecht et al., 2009). Although HIV prevalence is much lower in Nigeria than in other African countries the enormous size of Nigeria‘s population makes this prevalence to be a large number. The HIV pandemic has also significantly compromised the food security of affected households and communities, reducing the availability of productive labor, diverting income, depleting savings and productive assets and impeding inter-generational knowledge transfer (Watkins, 2007). In some contexts, food insecurity may lead to more migratory livelihood strategies and high-risk sexual behaviors that increase the risk of HIV transmission (Hecht et al., 2010).

ASSESSMENT OF NUTRITIONAL STATUS

Nutritional assessment is the evaluation of an individual‘s health status from a nutrition perspective. Ongoing assessment of nutritional and medical status is crucial to quality nutrition care for every person living with HIV. (Whitney and Rolfes, 2007). A complete base line nutrition assessment should be done for each patient for optimal care. Both baseline and ongoing assessment should examine changes in body composition as well as clinical and biochemical parameters. There are four principal approaches to nutritional assessment: clinical, anthropometric, dietary and biochemical (Whitney and Rolfes, 2007).

Clinical Nutritional Assessment:

A complete clinical assessment provides information about the patient‘s medical history as well as physical parameters related to nutrition care. A comprehensive medical history includes the followings; (a) Information on any existing nutrition-related issues (such as hepatitis, diabetes, obesity, renal disease, cardiovascular diseases, cancers, neurological diseases, oral health issues, and bone disorders);(b) Family history of nutrition-related diseases; and (c) Information about the patient‘s weight history and usual level of physical activity (Whitney and Rolfes, 2005).Other key areas to be addressed in the clinical assessment include the presence of any opportunistic infections that may affect intake or metabolism, gastrointestinal complications, potential food and drug interactions, the use of any complementary therapies, nutrition-related adverse effects from medications. (Whitney and Rolfes, 2007)

Anthropometric Nutritional Assessment:

Anthropometric measurements, including measures of body weight, body mass index, and subcutaneous fat stores, can help the nutrition professional identify and track changes in body composition. During the course of HIV treatment, the patient may experience muscle loss,subcutaneous fat loss, or fat hypertrophy,which may or may not be reflected in the patient‘s total body weight. For this reason, it is vital to assess body composition on a regular basis. The measurement of body composition may be done using a variety of techniques, such asbioelectrical impedance analysis (BIA), computed tomography(CT) scans, dual energy x-ray absorptiometry scans (DEXA), magnetic resonance imaging, or the use of skin calipers. Regular assessment of body weight and body composition can help in the early detection and treatment of morphologic changes, such as the loss, accumulation, and/or altered distribution of fat as well as AIDS wasting syndrome.

Dietary Nutritional Assessment:

Assessment of nutritional status based on dietary intake provides a record of an individual‘seating habits and food intake and can help identify possible nutrient imbalances. Recording dietary intake can be done using various ways such as 24 hours recall, the usual intake record and food frequency questionnaire. Food models or photos and measuring devices can also help to identify the type of foods and quantities consumed.

Biochemical Nutritional Assessment:

Biochemical parameters offer insight into the patient‘s nutritional status. Indicators of disease progression, micro nutrient status, metabolic syndrome, and comorbidities such as diabetes and hyper-lipidemia may be identified using biochemical assessment (Whitney and Rolfes, 2007).Ongoing biochemical assessment can help identify low levels of certain micro nutrients (such aszinc and selenium), which are common in HIV due to mal-absorption, alterations in metabolism, medication therapies, poor dietary intake, and accelerated nutrient turnover.Biochemical assessment can also help identify various types of anaemia that can occur with chronic HIV infection,including anaemia associated with inadequate nutrient intakes. Some biochemical measures may help predict outcomes of HIV infection.Research has suggested that low levels of serum albumin, vitamin A, vitaminB-12, and selenium may be associated with progression of HIV infection (Piwoz and Preble, 2000). Regular biochemical assessment including albumin, haemoglobin, serum iron, magnesium,vitamin levels, blood lipids, renal function, and liver enzyme levels will give the nutrition professional a more comprehensive picture of the patient‘s ongoing nutritional status and may help identify correctable nutritional deficiencies (Piwoz and Preble, 2000).

SOCIOECONOMIC CHARACTERISTICS

HIV/AIDS is a household name in Sub-Saharan Africa (SSA) and its toll on the general population is increasing daily. It is estimated that 1.9 million people were newly infected with HIV in Sub-Saharan Africa (SSA) in 2007, bringing the total number of people living with HIV in SSA to 22 million, which is about 67% of the global total of 32.9 million (WHO, 2008). The HIV/AIDS epidemics in SSA vary from country to country with most countries in Southern Africa (Botswana, Lesotho, Namibia, South Africa, Swaziland, Zambia and Zimbabwe) having a HIV prevalence rate exceeding 15% (WHO, 2008). Although it is generally accepted that the prevalence rate of HIV/AIDS in Nigeria is relatively low (ranges between 3.1 and 4.6%)compared to the rest of sub- Saharan Africa (FMoH, 2008; WHO, 2008), Nigeria‘s large population size means a significantly high number of people are infected. In fact, HIV has been reported among a broad spectrum of the Nigerian population including healthy persons, blood donors, clients of Sexually Transmitted Diseases (STDs) clinics, tuberculosis patients, long distance truck drivers, pregnant women attending antenatal clinics, Commercial Sex Workers (CSWs) and their clients, clinically ill and healthy persons, infants and youths (FMoH, 2008;Laah, 2003; Mamman, 2003). Although HIV/AIDS is prevalent in all population groups, data from most countries suggest that it is more pronounced among those who are within there productive and productive age group. Data from the United States of America (USA) showed that among youths age 20 to 24 years, 64% of reported HIV infections occurred among young men and 36 per cent among young women. While among youths age 13 to 19 years, 57% of reported HIV infections occurred among women and 43% among young men (Schneider et al.,2008). In Nigeria, as it is in many sub- Saharan African countries, prevalence of HIV/AIDS is predominant in the age group 15-24 years (Salako et al., 2012). In the early years of the epidemic, prevalence rates were found to be higher among men than among women in many countries of the world where HIV/AIDS was found in the population. Giriet al., (1995) in an earlier study of the socio-demographic characteristics of HIV infection in northern Italia using data obtained from a study of 134 patients testing positive to HIV antibody, revealed that adult male appeared to have the highest HIV rates. A similar study in Kuala Lumpur based on data collected between 1987 and 1995 noted that over two third of those infected w ere males (Cheong et al., 1997). In the last one-decade, the prevalence rates of the HIV/AIDS epidemic have been found to be higher in women than in men (Laah, 2003; Mamman, 2003; FMoH, 2008; NPC and ICF Macro, 2009).

Trend in HIV/AIDS

prevalence in Nigeria Since the first case of HIV/AIDS was diagnosed in Nigeria in 1986, the epidemic in the country has since extended beyond the high-risk groups to the general population. Nigeria has a rapidly growing HIV/AIDS epidemic that is characterized by a prevalence rate of 4.6% (UNAIDS and WHO, 2009) that is driven largely by heterosexual sex. Although there is a spatial variation in the HIV/AIDS prevalence in Nigeria as some parts of the country are more affected than others,there is no state or community that is not affected. Young people, especially women 20-24years old, are increasingly vulnerable. Other affected groups include sex workers and people with tuberculosis. The prevalence of the HIV/AIDS is fueled by low levels of male and female condom use, high rates of casual and transactional unprotected sex among young people,poverty, low literacy levels, cultural and religious factors, as well as stigma and discrimination (Mbakwen et al., 2012; NPC and ICF Macro, 2009; Inungu and Karl, 2010). Fig. 1 shows the trend in HIV/AIDS prevalence in Nigeria. The prevalence rate rose from 1.8% in 1991 to 5.8%in 2001, but between 2001 and 2005 the prevalence rate declined to 4.4% and increased to4.6% in 2008 (FMoH, 2008; Chukwukaodinaka, 2014; NPC and ICF Macro, 2009). Despite the fact that Nigeria is one of the largest oil producing nations in the world it is ranked 158 out of177 on the United Nations Development Program,(2007/2008) Human Poverty Index (Watkins,2007). The ranking of Nigeria as one of the poorest in the world means that Nigeria is faced with very daunting task of fighting the HIV/AIDS epidemic (Mbakwen et al., 2012). Given the current efforts and resources the effects of the HIV/AIDS are likely to be overwhelming in the years ahead.

HIV/AIDS AND NUTRITION

The HIV virus attacks the immune system. In the early stages of infection a person shows no visible signs of illness but later many of the signs of AIDS will become apparent, including weight loss, fever, diarrhoea and opportunistic infections (such as sore throat and tuberculosis).Good nutritional status is very important from the time a person is infected with HIV. Nutrition education at this early stage gives the person a chance to build up healthy eating habits and to take action to improve food security in the home, particularly as regards the cultivation, storage and cooking of food. Good nutrition is also vital to help maintain the health and quality of lifeof the person suffering from AIDS. Infection with HIV damages the immune system, which leads to other infections such as fever and diarrhoea. These infections can lower food in take because they both reduce appetite and interfere with the body‘s ability to absorb food. As a result, the person becomes malnourished, loses weight and is weakened, (Piwoz and Preble,2000).One of the possible signs of the onset of clinical AIDS is a weight loss of about 6-7 kg for an average adult. When a person is already underweight, a further weight loss can have serious effects. A healthy and balanced diet, early treatment of infection and proper nutritional recovery after infection can reduce this weight loss and reduce the impact of future infection.A person may be receiving treatment for the opportunistic infections and also perhaps combination therapy for HIV; these treatments and medicines may influence eating and nutrition. Good nutrition will reinforce the effect of the drugs taken. When nutritional needs are not met, recovery from an illness will take longer. During this period the family will have the burden of caring for the sick person, paying for health care and absorbing the loss of earnings while the ill person is unable to work. In addition, good nutrition can help to extend the period when the person with HIV/AIDS is well and working, (FMoH, 2008; WHO, 2008).

BIOCHEMICAL PARAMETERS

CD4 T-cells

T-cells are a subset of white blood cells that play an important role in the body's immune system. CD4 is, by contrast, a type of glycoprotein found on the certain immune cells like T-cells, macrophages and monocytes. CD4 T-cells are considered "helper" cells because they do not neutralize infections but rather triggers the body's response to infections. In response, CD8T-cells classified as such because of the type of glycoprotein on their surface play a part as so-called "killer" cells by producing antiviral substances (antibodies) that help fight off foreign invaders. One of the conundrums of HIV infection is that the very cells meant to initiate an immune defense are the same ones targeted for infection by HIV. As a retrovirus, HIV needs to infect certain "host" cells in order to make copies of it. CD4 cells are the prime targets for this in the course of an infection. During infection, HIV attaches to these helper cells, emptying its genetic material within so that the host's genetic coding can be altered to produce other HIV virus. In doing so, the host CD4 cell is killed, and its ability to trigger an immune defense is gradually depleted to such a point as to leave the body open to opportunistic infections. The dynamics of an HIV are such that "killer" CD8 T-cells are increasingly left blind in an 14advancing infection and eventually become unable to cope with the growing population of HIV(as measured by the viral load). If left untreated, the immune system will in all but rare cases completely collapse (or become compromised), (NIH, 2015).A simple blood test called the CD4 count estimates the number of functioning CD4 cells in acubic millimeter of blood. The higher the CD4 count, the stronger the immune function. In a healthy adult, a normal CD4 count can vary enormously (by population, age group, etc.) but is typically around 500 to 1500 cells per cubic millimeter of blood (ml). Traditionally, CD4counts have been used as means by which to determine when to start antiretroviral therapy(ART) and/or prophylactic drugs meant to prevent HIV-associated opportunistic infections. But in recent years that role has been played down as global authorities now aim to initiate treatment on diagnosis rather than waiting until the CD4 counts drop to below 500 cells/ml,(the previous initiation threshold). With that being said, the CD4 count is still central to the aging of the disease with counts below 200 cells/ml officially classified as AIDS (or acquired immune deficiency syndrome)(NIH, 2015).The CD4 count is also used to monitor an individual's response to therapy, with earlier initiation of ART generally correlating to more robust immune reconstitution. By contrast,people starting ART at very low CD4 counts (under 100 cells/mL) often have a more difficult time reconstituting their CD4 counts to normal levels, particularly after severe bout of illness.(May et al., 2012).

CHOLESTEROL

High levels of fats (including cholesterol) in the blood circulation, depending on how they are transported within lipoproteins, are strongly associated with the progression of atherosclerosis(arteriosclerotic vascular disease). Most ingested cholesterol is esterified and esterified cholesterol is poorly absorbed. The body also compensates for any absorption of additional cholesterol by reducing cholesterol synthesis (Lecerfand De Lorgeril,2011). For these reasons,seven to ten hours after ingestion, cholesterol will show little, if any, effect on total body cholesterol content or concentrations of cholesterol in the blood. However, during the first seven hours after ingestion of cholesterol, the levels significantly increase (Dubois et al.,1994).Cholesterol is recycled. The liver excretes it in a non-esterified form (via bile) into the digestive tract. Typically, about 50% of the excreted cholesterol is reabsorbed by the small bowel back into the bloodstream.Animal fats are complex mixtures of triglycerides, with lesser amounts of phospholipids and cholesterol. As a consequence, all foods containing animal fat contain cholesterol to varying extents(William, 2003). Major dietary sources of cholesterol include cheese, egg yolks, beef, pork, poultry, fish, and shrimp(Jensen et al., 1978). Human breast milk also contains significant quantities of cholesterol(William, 2003).

HDL-CHOLESTEROL

HDL is the smallest of the lipoprotein particles. It is the densest because it contains the highest proportion of protein to lipids. Its most abundant apolipoproteins are apo A-I and apo A-II. (Arare genetic variant, ApoA-1 Milano, has been documented to be far more effective in both protecting against and regressing arterial disease; atherosclerosis). HDL transports cholesterol mostly to the liver or steroidogenic organs such as adrenals, ovary, and testes by both direct and indirect pathways. HDL is removed by HDL receptors such as scavenger receptor BI (SR-BI),which mediate the selective uptake of cholesterol from HDL(Gebhardtet al., 2008).

LOW-DENSITY LIPOPROTEIN

Low-density lipoprotein (LDL) is one of the five major groups of lipoproteins. These groups,from least dense to most dense, are: chylomicrons , very low-density lipoprotein (VLDL),intermediate-density lipoprotein (IDL), LDL, and High Density Lipoprotein (HDL), all of them, particles far smaller than human cells. In nutrition, LDL is sometimes referred to as "the bad cholesterol." Lipoproteins transfer fats around the body in the extracellular fluid, can be sampled from blood and allow fats to be taken up by the cells of the body by receptor-mediated endocytosis (Dashtiet al.,2011). Lipoproteins are complex particles composed of multiple proteins which transport all fat molecules (lipids) around the body within the water outside cells. They are typically composed of 80-100 proteins/particle (organized by a single Apo B for LDL and the larger particles). A single LDL particle is about 260-300 nm in diameter(submicroscopic ) typically transporting 3,000 to 6,000 fat molecules/particle, varying in size according to the number and mix of fat molecules contained within. The fats carried include cholesterol, phospholipids, and triglycerides; amounts of each vary considerably.LDL particles pose a risk for cardiovascular disease when they invade the endothelium and become oxidized, since the oxidized forms are more easily retained by the proteoglycans. A complex set of biochemical reactions regulate the oxidation of LDL particles, chiefly stimulated by presence of necrotic cell debris and free radicals in the endothelium. Increasing concentrations of LDL particles are strongly associated with increasing rates of accumulation of atherosclerosis within the walls of arteries over time, eventually resulting in sudden plaque ruptures and triggering clots within the artery opening, or a narrowing or closing of the opening, i.e. cardiovascular disease, stroke, and other vascular disease(Dashtyet al., 2014).

BODY MASS INDEX

The body mass index (BMI) or Quetelet index is a value derived from the mass (weight) and height of an individual. The BMI is defined as the body mass divided by the square of the body height, and is universally expressed in units of kg/m2, resulting from mass in kilograms and height in metres. The BMI may also be determined using a table or chart which displays BMI as a function of mass and height using contour lines or colors for different BMI categories, and may use two different units of measurement (Eknoyan, 2008).The BMI is an attempt to quantify the amount of tissue mass (muscle, fat, and bone) in an individual, and then categorize that person as underweight, normal weight, overweight, or obese based on that value. However,there is some debate about where on the BMI scale the dividing lines between categories should be placed.Commonly accepted BMI ranges are underweight: under 18.5, normal weight:18.5 to 25, overweight: 25 to 30, obese: over 30 (Eknoyan, 2008).

DIETARY PATTERNS

Having proper nutrition in HIV/AIDS includes; consuming diversified or variety of foods that will provide the body with the necessary energy, protein, fats, vitamins and minerals (FMOH,2008).

Food Diversity in Management of HIV/AIDS

Dietary diversity, the consumption of an adequate variety of food groups, is an aspect of dietary quality and can be considered an indicator of general nutritional adequacy (Mpontshaneet al.,2008). Low dietary diversity is associated with specific nutrient deficiencies. The main reason for promoting food diversification is that, no single food except breast milk contains all the nutrients the body needs in the right quantities and combinations (FMOH, 2008). Another study by Bukusubaet al., (2007) noted that there is very low dietary diversity in developing countries,the majority of studied households reported consuming fewer than six food groups (low quality diet)moreover their daily diet was dominated by one main staple food group mainly cereals. According to Castleman et al., (2004), maintaining adequate nutritional status means consuming a variety and adequate quantity of foods to meet energy, protein, and micro nutrients needs. PLHIV should eat balanced and diverse diets consisting of starchy staples with cooked legumes, nuts and animal foods, fat and oil, fruits, and vegetables. A study by Mpontshaneetal., (2008) showed that in South Africa, diets for PLHIV were significantly less diverse than those of HIV negative individuals. However a balanced diet will ensure that the individual 18consumes sufficient nutrients to maintain energy, normalize weight, and ensure the body‘s proper functioning. The main types of food people need to live a healthy life include energy-providing foods (i.e. carbohydrates, fats), body-building foods (i.e., proteins, minerals), and protective foods (i.e., vitamins, minerals) (Castlemanet al., 2004).

Energy Giving Foods

This includes the carbohydrates, fats and oils that are in food groups like cereals, tubers, and plantain. Staples are good sources of energy. Staple foods should be the part of every meal and form the base and largest part of daily meals.Cereals Cereals are one of the staple foods in Africa and other parts of the world. Examples of cereals are maize, sorghum, millet, rice etc. Some cereals such as millet and sorghum contain some proteins and iron. However, they don‘t contain adequate nutrients on their own. Nutrients from staple foods may not be available to the body unless eaten in combination with other foods,(Williams et al., 2003).

Roots &Tubers

Tubers are known as good sources of energy. The most common tubers and roots that are consumed in Nigeria are sweet potatoes, cassava, yams, etc.Fats/Oils and Dairy products Fats and oils are the richest sources of energy. One gram of fat provides twice the energy of one gram of carbohydrate. Therefore people only need small amount of fats because excessive consumption of fats may predispose individuals to obesity and heart disease. Vegetable oils are obtained from corn, sunflower, cotton seed, shear butter, palm oil and margarine. Animal source fats include butter, cheese, whole milk, fatty meat and fish (including fish oil). Fat also facilitate absorption and utilization of some essential vitamins such as A, E, D and K.(Williamset al., 2003)

Body-Building Foods

Proteins are referred to as body-building foods. They are essential for cell growth, support the function and formation of the general structure of all tissues, including muscles, bones, teeth,skin and nails. The two main types of proteins are: plant source proteins and animal source proteins. Plant source proteins include beans and peas of different varieties, green grams,groundnuts, and soybeans, whereas animal source proteins include meat, milk (including products like cheese, yoghurt and fermented milk), fish and eggs. Williams et al. (2003) found that high protein diets are associated with increased gain of Body cell mass among HIV positive persons.

Legumes

Legumes include beans, peas, lentils, groundnuts, and soybeans. Legumes provide nutrients that are needed to develop and repair the body as well as building strong muscles. As compared to animal products, legumes provide cheaper source of protein and energy. Legumes when eaten with staple foods such as maize, millet, sorghum and rice, improve quality of the diet.Legumes are also rich in other essential nutrients including: the B vitamins, vitamin E, iron,and calcium.

Animal Products

Animal products supply good quality proteins, vitamins, minerals and extra energy. Micro nutrients in animal products include iron, vitamin A, selenium and zinc that strengthen muscles and immune system. Animal products include beef, chicken, fish, eggs, offal and milk.

Protective Foods

Fruits and vegetables are known as protective foods because they provide vitamins and minerals that are important in strengthening the immune system. Vegetables and fruits are also major sources of fibre and roughage required for bowel movement and prevention of constipation.

Vegetables

Vegetables add taste, flavour and colour to our meals. Common vegetables include: spinach, ugu leaves, pumpkin leaves, cowpea leaves, carrots, cassava leaves, and green peppers.Cabbage is a vegetable that is important mainly as roughage. Vegetables contain useful immune substances called beta-carotenes. In many cases, vegetables are seasonal in availability, quality and prices. Hendricks et al., (2003) noted that HIV patients who consume high fibre foods have shown lower fat deposition in their bodies.

Fruits

A variety of fruits are grown in Nigeria. The deep yellow or orange coloured fruits are richer in vitamins, particularly beta-carotenes and vitamin A. Such fruits include avocadoes, mangoes, pawpaw, pumpkin, passion fruit, pineapple and jackfruit. Oranges, lemons and other citrus fruits are rich sources of vitamin C. Like vegetables, most fruits in Nigeria are seasonal. Fruits are known as good sources of antioxidant substances (Castlemanet al., 2004).

Meal Frequency

The guideline by WHO (2005) on nutrition for PLHIV encourages people living with HIV to increase the amount and frequency of eating meals that are rich in energy, protein and plenty of fruits and vegetables. It also encourages eating of two to three snacks in addition to the main daily meals (Breakfast, lunch and Supper). By increasing meal frequency, PLHIV can meet the higher energy requirement of the body which is due to infection.

Nutrient Requirements of PLHIV

In general, PLHIV have different nutritional requirements than HIV negative person.Furthermore the nutrient requirements with in PLHIV can also be different depending on the progress of the infection. (Macallanet al., 1995) stated that poor dietary intake among HIV patients contributes to loss of lean mass or poor recovery among people with severe malnutrition.

Macro nutrient Requirements

Energy Requirement Energy requirements are elevated with high viral load, fever, opportunistic infection, the need for weight gain and the increased energy cost of breathing in respiratory infections (Xuereb,2004). According to WHO (2003) recommendation, for symptomatic HIV positive adults should increase energy intake by 10% and 20-30%during the symptomatic phase over the requirement for healthy HIV positive people of the same age, sex, and physical activity level.These recommendations are also for PLHIV persons, including those taking HIV-related medications such as ARVs (Castlemanet al., 2004). Researchers in United States found that weight gain and /or weight maintenance could be achieved among asymptomatic HIV positive individuals and among HIV positive people in the early stages of AIDS with no secondary infections, who received at least one day, high-energy, high protein, and liquid food supplementation along with nutritional counseling, (Stack et al.,(1996).

Protein Requirement

According to WHO (2003), data are insufficient to support an increase in protein requirements due to HIV infection. HIV-positive persons do not require more protein than the level recommended for healthy HIV negative persons of the same age, sex, and physical activity level, that is, 12% to 15% of total energy intake. However, Xuereb (2004) noted that, since energy requirements are higher, protein intake should increase proportionately with efforts to increase energy intake. On the other hand, there is the view that requirements are consistently elevated to provide substrate for immune cell replication (the acute phase response) lean body mass maintenance as well as during periods of septicaemia when protein needs are dramatically elevated to attenuate hyper catabolism of somatic protein stores. Protein deficiency is closely associated with energy deficiency: both are often deficient in HIV/AIDS. Water low et al. (1992) stated that establishing the amount of protein which an individual needs to maintain body composition and body function is difficult. Current evidence on macro nutrient and HIV infection by WHO (2005) suggested that HIV positive individuals in a state of dietary protein depletion need greater amounts of protein. However more evident from animal and human studies models on septic or catabolic states similar to HIV/AIDS show inadequately utilized-amino acid from increased intake. (Tomkins et al., 1983 and Powellet al., 1984).

Fat Requirement

According to the WHO (2003) guidelines, there is no evidence that fat requirements are different during HIV infection. However, certain ARVs or certain infection symptoms such as diarrhoea may require changes in the timing or quantity of fat intake (Castleman et al.,2004).Despite the well documented evidence on fat mal-absorption in HIV/AIDS, Castaldoet al.(1996) suggested that it was possible to achieve nutritional rehabilitation using diets rich in fat.

Micro nutrient Requirements of PLHIV

Micro nutrients (Vitamins and minerals) are important in the HIV-nutrition relationship due to their critical roles in cellular differentiation, enzymatic processes, immune system reactions,and other body functions, (Piwoz and Preble, 2000). Several micro nutrients are required by the immune system and major organs to fight infectious pathogens. Persons with inadequate intake of micro nutrients have difficulty in resisting infection. As a result, the role of micro nutrients in HIV/AIDS takes on special importance in individuals and populations with marginal or low micro nutrient intakes (Friiset al., 2001). Although micro nutrients requirements are likely to be reduced when the HIV patient is put on ARV, micro nutrient deficiencies may persist and affect absorption and efficacy of drugs. Zinc Zinc is known for its role in functioning of many enzymes, immune reactions, transport of vitamin A and also it acts as an antioxidant (Castlemanet al., 2004). Meat, fish, poultry, shellfish, whole grain cereals, legumes, vegetables and pumpkin seeds are the main sources of zinc (Castlemanet al., 2004). In populations where there is a mild and marginal zinc deficiency,problems like depressed immunity, damage to epithelial lining of the intestine and respiratory tract are common. Zinc may have indirect effect on controlling of weight loss and wasting where as zinc inhibits tumor necrosis factor (TNF), a cytokine that is important in triggering the process of wasting in HIV infection, (Baumet al., 2000).

Iron

Iron has a vital role for all cells in generating energy. Iron is required by the body to produce new cells, amino acids, and hormones, as antioxidant and it is transported throughout the body to be used as needed. Iron is found in muscle, in blood, and in many enzymes required for metabolism, (Piwoz and Preble, 2000). Dietary sources of iron include red meat, poultry,shellfish, egg, peanut, groundnuts, deep green leafy vegetables, lentils, beans, cereals (Castleman et al., 2004). Iron deficiency occurs mainly when the iron stores are depleted and the dietary intake of the patient can not compensate for these requirements.

CHAPTER SUMMARY

In this review the researcher has sampled the opinions and views of several authors and scholars on the topic under study. The works of scholars who conducted empirical studies have been reviewed also. The chapter has made clear the relevant literatures.