3200 Calories In 1945, 2640 Calories In 2010. But We Weigh More.

Did you happen to notice in that 1945 Minnesota Starvation Experiment that Gary Taubes recalled in his recent article, the following description of the mens’ pre-study diet?

Control Period (12 weeks): This was a standardization period when the subjects received a controlled diet of approximately 3,200 calories of food each day. The diet of the subjects who were close to their “ideal” weight was adjusted so as to maintain caloric balance, while the diets of the underweight and overweight individuals was adjusted so as to bring them close to their ideal weight. On average, the group ended up slightly below their “ideal” weight.

The men were fed ~3,200 calories/day and the group ended up slightly below their ideal weight.

Here’s a photograph of the group before the calorie-limiting part of the experiment:

My impression is … those are a lot of calories and the men aren’t that big.

This photograph is from the 1930s, a decade that saw mens’ beachwear tops come off.

An aside… While I was browsing for what men in the 1940s looked like, I came across the site: Beefcake Swimwear: A Visual Scrapbook Of Vintage Men’s Beachwear. It’s just a snapshot, if you will, but it does reveal mens’ body shapes over the decades. For a long time it was considered indecent for a man to uncover his chest. How times have changed.

Back to the present. The Dietary Guidelines for Americans 2010 give this information about mens’ calorie needs today, and their actual intake:

The estimated calorie needs of a moderately active male, 19 to 30 years old is 2,600 to 2,800 calories/day.

On the basis of national survey data, the average calorie intake among women and men older than age 19 years are estimated to be 1,785 and 2,640 calories per day, respectively.

It looks like men today are eating fewer calories than decades previous, yet they’re heavier. This chart says that in 1962 slightly less than half our population was overweight/obese. By 2000, 70% were overweight/obese. By 2010 it rose to 75%.

National Institutes of Health: Trends in Overweight and Obesity among Adults, United States, 1962–2010

You could speculate until the cows come home. Some people will say we move less. Some will say people lie about what they eat. Some will say the macronutrient (protein/fat/carbohydrate) content of our diets has changed. Maybe we smoked more or snacked less years ago. Me? I think there’s a significant contribution from chemicals in our food, chemicals that act as endocrine disruptors, chemicals that weren’t so abundant years ago. GMOs and their attendant pesticides (Roundup Ready) have been available since the 1980s. Take another look at that weight graph.