Tag Archives: calorie consumption over time

Are We Fat Because We’re Less Active?

Less active

Much of the world has seen a significant decline in populaton-wide physical activity over the last few decades, according to Nike-sponsored research reported in Obesity Reviews.

Countries involved with the study are the U.S., U.K., Brazil, China, and India.  How did they measure activity levels?

Using detailed historical data on time allocation, occupational distributions, energy expenditures data by activity, and time-varying measures of metabolic equivalents of task (MET) for activities when available, we measure historical and current MET by four major PA domains (occupation, home production, travel and active leisure) and sedentary time among adults (>18 years).

The authors note the work of Church, et al, who found decreased work-related activity in the U.S. over the last half of the 20th century.

Inexplicably, they don’t mention the work of Westerterp and colleagues who found no decrease in energy expenditure in North American and European populations since the 1980s.

More active

My gut feeling is that advanced populations around the globe probably are burning fewer calories by physical activity over the last 50 years, if not longer, thanks to technologic advances.  We in the U.S. are also eating more calories lately.  Since the 1970s, average daily consumption by women is up by 150 calories, and up 300 by men.  I’m surprised we’re not fatter than we are.

Steve Parker, M.D. 

Sources of Calories in U.S. Diet Over Last Four Decades

Italian seaside totally unrelated to this post

Do you ever wonder how many of the total calories in the aveage U.S. diet come from added sugars? Grains? Dairy products? Added fats?

You’d have to do some detailed nutrient analysis to get your personal numbers, but if you’d like U.S. averages, see this cool infographic at Civil Eats.

The graph also shows how many calories are or were available for consumption per capita over time (without accounting for wastage in restaurants). It’s based on U.S. Department of Agriculture data.

A superficial glance suggests that U.S. per capita daily calorie consumption has increased by about 600 from the 1970s until now. But remember, these numbers don’t discount for restaurant wastage. Nor do I see an adjustment for children versus adults. I’ve seen other calculations of an extra daily 150 calories (women) to 300 calories (men). Even the lower numbers could explain our explosion of overweight and obesity.

Steve Parker, M.D.