The U.S. adult population in the 1970s ate an average of 2400 calories a day. By the 2000s, our calories were up to 2900.
Putting a face on the statistics
What did average adult weight do as we increased daily calories by 500? It increased by 8.6 kg, from 72.2 to 80.6 kg. In U.S. units, that’s a 19 lb gain, from 159 to 178 lb.
Children increased their average intake by 350 cals/day over the same time frame.
If I recall correctly, I’ve seen other research suggesting the daily calorie consumption increase has been more like 150 to 350 per day (lower end for women, higher for men). I suspect these latter figures are more accurate.
Details are in the American Journal of Clinical Nutrition.
The study authors don’t say for sure why we’re eating more, but offhand mention an “obesogenic food environment.” They don’t think decreased physical activity is the cause of our weight gain; we’re fatter because we eat too much.
Steve Parker, M.D.
h/t Ivor Goodbody
Ivor Goodbody in a recent tweet reminded me of an interesting nutrition science article. Ian Spreadbury hypothesizes that carbohydrate density of modern foods may be the cause of obesity. Refined sugars and grains—types of acellular carbohydrates—are particularly bad offenders.
Harvesting acellular carbs
These acellular carbs may alter our gut microorganisms, leading to systemic inflammation and leptin resistance, etc. Our Paleolithic ancestors had little access to acellular carbohydrates.
Read more about it in “Comparison with ancestral diets suggests dense acellular carbohydrates promote an inflammatory microbiota, and may be the primary dietary cause of leptin resistance and obesity,” in Diabetes, Metabolic Syndrome and Obesity: Targets and Therapy, 2012, vol. 5, pp. 175-189.
To reverse our modern obesity epidemic, we need better understanding of the underlying pathophysiology.
PS: For Spreadbury’s formal definition of acellular carbohydrates, see my long comment below.