A diet rich in fibre, high in protein and providing plenty of calories appears to be protective against gaining central visceral fat (lipohypertrophy) in men, according to a study published in a recent issue of the American Journal of Clinical Nutrition.
This is the first study to identify a diet rich in protein and relatively high in calories as one which may prevent the fat gain associated with lipodystrophy in men. The study also identified weight training and not smoking as other important factors in not acquiring central visceral fat gain, strategies examined and suggested in the October issue of AIDS Treatment Update.
Researchers in New England already involved in a long term study of nutrition and HIV - the Nutrition for Healthy Living study - identified 75 men in the study who fit their definition of central fat deposition: a waist-to-hip ratio greater than 0.95. They set about finding others in the study who were similar in terms of age, race, HAART use, length of follow-up and CD4 cell count, and found 47 controls i.e. men who did not have their definition of central visceral fat gain, but who were also not wasting or obese.
By comparing their diets (assessed by the gold standard of 3-day diet records, averaged over at least two visits of at least six months) and lifestyles - but notably not their medications nor their glucose or insulin levels - the researchers identified diet and lifestyle differences between those with central fat gain and those without.
The researchers admit that they were looking for differences in fibre intake - since fibre has been shown to lower blood glucose and lower serum cholesterol in HIV-negative people - and they found it. Intake of soluble fibre (e.g. oatmeal), insoluble fibre (most fruit and vegetables) and total dietary fibre were all significantly higher in those without central fat accumulation. This has been seen before in other studies looking at lipodystrophy and diet, and is not surprising.
However, one particular type of soluble fibre, pectin, was associated with the most significant magnitude of risk reduction of having central fat accumulation: about 30% for each 1 gram increase of pectin intake a day. Pectin is found in the cell walls of most fruits, especially apples and berries, and since it absorbs water in the gut, has been recommended as a dietary method of dealing with diarrhoea. It has also been found to reduce total and LDL cholesterol in HIV-negative people with high cholesterol. Pectin is found in large amounts in apple sauce and can be also be taken as a dietary supplement.
Another surprising finding was the association between protein intake and central fat accumulation. The difference in total protein was an average of 106 grams/day in those with central fat accumulation and 119 grams/day in those without (p=0.01). The researchers calculated a 2% risk reduction in acquiring central fat accumulation for every 1 gram of protein eaten. Although total difference in calories was not different, the ratio of calories consumed to body weight was found to be significantly higher (p=0.03) in those without central fat accumulation. This might appear to be counterintuitive to those who believe fat gain due to lipodystrophy is the same as weight gain: the authors attempt to explain the difference by suggesting those without central fat gain may have higher levels of physical activity and burn calories doing activities like weight training.
Notably, given the recent interest in low carbohydrate diets (e.g. Atkins) no difference was found with regard consumption of carbohydrates. Additionally, no difference was seen in consumption of fats, cholesterol, alcohol, or micronutrients. Resistance training was performed significantly more often (p=0.05) by those without central fat accumulation, and those with central fat accumulation were more likely to be smokers (p=0.05) than those without, although neither of these were associated with eating more or less healthily, according to the definitions of this study.
This study was only undertaken in men with central fat accumulation and may not be relevant to women who appear to have different patterns of lipodstrophy-associated fat gain. This study also did not thoroughly examine the metabolic complications associated with lipodystrophy and therefore cannot be used to determine the best diet to treat high cholesterol or triglycerides. Additionally, since they did not look at other confounding factors - like which antiretrovirals the men were taking - it is impossible to draw firm conclusions about the relationship between central fat gain and HIV-associated lipodystrophy.
However, the authors do sensibly emphasise "the importance of overall good nutrition, especially adequate energy and protein intakes" and "suggest that a healthy lifestyle, including diet, resistance training, and avoidance of unhealthy habits such as smoking, may be beneficial in preventing the development of fat deposition."
Further information on this website
Fat loss in all body regions most common form of lipodystrophy in women - news
Is lipodystrophy caused by the action of antiretroviral drugs in the brain? - news
Hendricks KM et al. High-fiber diet in HIV-positive men is associated with lower risk of developing fat deposition. Am J Clin Nutr 78: 790-5, 2003.