|Is the USDA to blame for this?|
In the corresponding paper, the authors present the first comprehensive analysis of that data, documenting how macronutrient consumption patterns and the weight and body mass index in the U.S. adult population evolved since the 1960s. What they found is... well, not exactly in support of what the USDA did over the past decades.
In 1961, spurred by emerging medical and epidemiological research, the AHA issued dietary recommendations to “reduce the intake of total fat, saturated fat, and cholesterol” (Kritchevsky. 1998). In 1977, the U.S. Senate Select Committee on Nutrition and Human Needs issued Dietary Goals for the United States (“Dietary Goals”), which recommended that fat consumption be reduced to 30% of energy intake, and that carbohydrate consumption be increased to account for 55-60% of energy intake (SCNH. 1977).
In short: The feds told the US citizens to eat more carbohydrates and less fat and the public obeyed. According to the official USDA data (at least most of it is from the NHANES studies) the scientists analyzed, the fat consumption by U.S. adults has decreased from 45% to 34% between 1965 and 2011. At the same time, the intake of carbohydrate has increased from 39% to 51%.
|Figure 1: The recommended changes in dietary habits went hand in hand with the increase in BMI (Cohen. 2015),|
"In the first comprehensive statistical analysis using all available NHANES surveys, this paper demonstrates that general adherence to government dietary recommendations to decrease fat share of total dietary intake has been accompanied by a rapid increase in obesity rates.
Figure 1b: What forget is that their data also shows that the absolute amount of fat US citizens consumed (in g | see Figure 1b) did not decrease. So, essentially the claim that the US citizens followed the guidelines is questionable.
The results in this paper compel a full analysis of the potential causal relationship between Americans seeming adherence to the government’s nutrition recommendations and obesity" (Cohen. 2015).Now as convincing as this may seem to the laymen, the scientists are careful enough to use the important wort "potential" in the conclusion of their analysis of the data. A small word with far-reaching implications. Firstly, the absolute data in Figure 1b shows that there is no decrease in absolute fat consumption. A fact that leads me to a second, more important point. Th relative reduction in fat intake went hand in hand with other changes in the US diet. Mostly, an increase in total energy intake which came mostly from carbohydrates (see Figure 1b). But there is more: Examples?
- Cohen, Evan, et al. "Statistical review of US macronutrient consumption data, 1965–2011 Americans have been following dietary guidelines, coincident with the rise in obesity." Nutrition (2015).
- Jahns, Lisa, Anna Maria Siega-Riz, and Barry M. Popkin. "The increasing prevalence of snacking among US children from 1977 to 1996." The Journal of pediatrics 138.4 (2001): 493-498.
- Kritchevsky, David. "History of recommendations to the public about dietary fat." The Journal of nutrition 128.2 (1998): 449S-452S.
- Nielsen, Samara Joy, and Barry M. Popkin. "Patterns and trends in food portion sizes, 1977-1998." Jama 289.4 (2003): 450-453.
- Nielsen, Samara Joy, and Barry M. Popkin. "Changes in beverage intake between 1977 and 2001." American journal of preventive medicine 27.3 (2004): 205-210.
- Select Committee on Nutrition and Human Needs of the United States Senate. Dietary goals for the United States [Internet]. 2nd ed. Washington: U.S. Government Printing Office; 1977.
- Swinburn, Boyd, Gary Sacks, and Eric Ravussin. "Increased food energy supply is more than sufficient to explain the US epidemic of obesity." The American journal of clinical nutrition 90.6 (2009): 1453-1456.