Books about middle age weight gain or abdominal fat accumulation, as it’s known in professional circles, are flying off the shelves as a record number of the US population enters their golden years. This generation, brought up on the fat phobic diet that made fat intake of any kind an inexcusable excess, is now seeing the result of this mistaken dietary guidance. By avoiding the demonized macronutrient (fat) in an effort to avoid heart disease in later life, today’s baby boomers may have set themselves up for sarcopenia or age related muscle loss and the dangerous abdominal fat accumulation, a contributor to heart disease. How is this possible? The answer lies in the unintended consequence of reducing protein intake while avoiding fat.
During the years 1970-2000, Americans were advised to lower their fat intake which resulted in reducing intake of foods high in protein like beef, pork, eggs, milk and butter. The assumption had been and still remains, that Americans consume a surplus of protein and protein recommendation need only keep Americans from negative protein balance. Optimal protein intake for supporting health was not a goal. However, recent research is beginning to accumulate which indicates a role of protein, in particular the level of specific branch chain amino acids (BCAA) in proteins, that is associated with a lower prevalence of obesity and overweight in middle age adults.
A recent study published in Journal Nutrition1, looked at the association between BCAA intake and the risk of overweight/obesity status in a cohort of 4429 Asian and Western adults. The study was a part of a larger International Study of Macro-/Micronutrients and Blood Pressure Study (INTERMAP) which did not include any intervention in the methodology other than recording dietary recall and 24 hr. urinary measurement. Results confirm the hypothesis that across an international population, dietary intake of branch chain amino acid intake was inversely associated with prevalence of overweight status amongst healthy middle age adults and with the prevalence of obesity in Western adults. These results confirm earlier animal studies that have found higher leucine intake (BCAA) associated with lower body weight and fat mass gain.
1 Qin, LQ et al. J. Nutr. 141:249-254, 2011
Source: U.S. Department of Agriculture, Agricultural Research Service. 2011. USDA National Nutrient Database for Standard Reference, Release 24. Nutrient Data Laboratory Home Page, http://www.ars.usda.gov/ba/bhnrc/ndl