The World Food Programme (WFP) and the Food and Agricultural Organization (FAO) of the United Nations have tailored interventions to address malnutrition and HIV in many of the most heavily affected countries in sub-Saharan Africa. Most of these programs deliver staple foods to areas of scarcity or agricultural training and assistance to promote local production, in a community-level effort to prevent the development or arrest the progression of malnutrition. This “food first” approach is predicated on the observation that the prevalence and severity of a range of diseases are increased in poorly nourished populations. A distinction is necessary, however, between supplementary feeding, which is the provision of food rations (either local staples or specialized foods) to vulnerable or malnourished persons to supplement the local diet and provide balanced and/or adequate daily energy intake, versus therapeutic feeding, which aims for the nutritional rehabilitation of severely malnourished adults with specialized foods that are often energy and nutrient dense. Whether an intervention represents supplementary and therapeutic feeding may depend on the target population or the program intent, but some products may be more suitable to the latter.
The optimal composition of macronutrient supplementation for malnourished adults is still a matter of debate. As a replacement or an addition to local staple foods, three candidate supplements are commonly referenced: high-energy Ready-to-Use Therapeutic Foods (RUTF) [91
], corn-soya blends [92
], and fortified blended foods (FBF) [93
]. RUTF is a type of highly nutrient-dense spread (HNDS), a food product high in energy and micronutrients in which all powdered ingredients are suspended in fat and do not require any preparation or the addition of water before ingestion. RUTF, like other HNDS, can be stored for long periods, do not require refrigeration, and can be individually packaged and used effectively in areas where hygiene conditions are not optimal. RUTF has been used successfully for community therapeutic care and nutritional rehabilitation in the pediatric population [94
] and recommended by WHO for the management of severely malnourished children [97
]. Corn-soya blends, also referred to as High-Energy Protein Supplements, are blended flours which have been used effectively in the past in both emergency and protracted food relief operations [98
]. Corn-soya blends provide a higher calorie and protein content than many local carbohydrate-rich staple foods they are programmed to replace, but concerns have been raised regarding their suitability for the treatment of severe malnutrition given the low essential fatty acid and overall lipid content [99
]. FBF are also blended flours designed to provide more comprehensive nutrition supplementation, and contain mixtures of cereals (typically corn or wheat), pulses, fats, vitamins and minerals. The WFP distributed almost 300,000 metric tons of FBF in 2006 [100
]. compares the nutritional content of these supplements and local staples.
Comparison of the three major types of macronutrient supplements proposed for use in sub-Saharan Africa
RUTF has the advantage of higher calorie-to-weight and calorie-to-volume ratios than blended flours, which makes transporting a monthly ration easier [91
]. The standard packaging of blended flours in bulk adds uncertainty to the size of the daily ration consumed by the patient. Since patients with advanced HIV often rely on others for food preparation, there is greater likelihood that the ration will be shared [101
]. The higher viscosity of RUTF allows for higher levels of vitamin and mineral supplementation without sedimentation during storage, and the physical structure of a spread (i.e. powder mixed into fat) limits exposure to air and prevents vitamin oxidation. The low water content (2% compared to 8–12% for flours) prevents soluble minerals from interacting with vitamins, and decreases bacterial and insect contamination [102
]. E. coli
introduced into supplementary spreads do not grow, while they grow exponentially in a liquid form [99
]. RUTF, however, is not without its drawbacks. It is approximately three times more expensive to produce and requires more sophisticated processing facilities [103
]. A recent qualitative study by Medicins Sans Frontiers found that some patients were unable to carry home more than a 2-week ration of RUTF (approximately 5.1 kg). Half of the patients were unable to consume the entire daily ration due to poor taste, dietary boredom, or HIV-related complications such as thrush [104
Our review of the medical literature identified two randomized trials of nutritional supplementation for HIV-infected adults in sub-Saharan Africa () [24
]. A study by Cantrell et al compared ART adherence among persons receiving WFP rations and persons enrolled in clinics not yet receiving food aid. Criteria for assistance were based on household food insecurity, not anthropometrics, and the mean patient BMI in the intervention and control group was 21.0 and 20.8 (women) and 19.6 and 19.7 (men), respectively. Patients in the intervention group were more likely to achieve 95% monthly ARV adherence than patients in the control group (RR 1.5; 95% CI 1.2 to 1.8), but there was no significant difference in weight gain, CD4+ cell response, or mortality. However, the study lacked sufficient power to detect small but potentially relevant weight change differences between groups (e.g. 1–2 kg).
Trials of Macronutrient Supplementation in HIV-Infected Adults in Resource-Constrained Settings
A recent trial in urban Malawi randomized 491 adults initiating ART with a BMI <18.5 kg/m2 to receive 1,360 kcal/day of CSB or Ready-to-Use Fortified Spread (RUFS), similar to RUTF, for 3.5 months. There was not a study arm without nutritional supplementation. After 3.5 months, patients receiving RUFS has a significantly greater increase in BMI (2.2 ±1.9 vs. 1.7 ± 1.6 kg/m2) than those receiving RUFS, buts there were no significant differences in survival, HIV viral load, CD4 count change, or quality of life.