There's a video making the rounds again lately (despite being circa 2013-14) about an Iowa science teacher who used himself for an "experiment" with his class to eat exclusively at McDonald's. However, there were caveats, and the results surprise some people. As usual there's more to the story.
The video linked below is posted on youtube by McDonald's. So if you watch it, keep in mind that it's marketing and deserving of skepticism. (I didn't embed it because it's an "unlisted" video. Go figure.)
https://www.youtube.com/watch?v=rPp27kQpkmE
Here's the gist of the story.
An overweight science teacher initiated a project with some students that would have him eat three meals a day every day at McDonald's but limit his total calories to 2000 and meet daily nutritional requirements (from the FDA) for 14 unspecified nutrients. Also, he would walk 45 minutes a day for exercise. The food could include anything: Big Macs, french fries, etc. But in order to hit the nutrient profiles, some veggies were required so most days probably included a salad at least. Definitely not a super giant salad, but whatever.
The original three-month project was extended to six months (with increased exercise for the second three months) and after six months (or 180 days for 540 meals) he lost about 60 pounds while significantly improving health measures such as total cholesterol (which is a silly measure--why add two values when you want one to be low and the other high?), triglycerides, and blood pressure. The McDonald's-friendly conclusion is that eating fast food is OK--it's really about the choices we make.
Here are some StrongFasty thoughts about this.
First, it's not surprising that he lost weight: he was in a caloric deficit. (He was consuming fewer calories than required for weight maintenance.) Plugging in some guesstimates with some known values (his weight, gender, and age) gives an estimated maintenance value of about 2,900 calories per day. That means he was in a big caloric deficit, mostly from the diet restriction--about 900 calories--and a little more from the extra walking--about 200 calories--for a total of about 1100 calories a day. That's a lot! It's roughly 37% of his daily maintenance calories. This led to about 2.3 pounds per week of weight loss on average. (His maintenance calories would decrease as he lost weight, and the calories burned would increase when he raised the exercise intensity, but let's keep it simple.)
Also not surprising is that blood markers and pressure improved with the weight loss. Dropping unwanted pounds will do that for you.
Now, on to the more interesting (to me, anyway) points.
- One rather surprising thing is that a science teacher didn't do science. The sample size of one is meaningless. There were no control groups (e.g., people changing their diet but not exercising and vice versa). This is one poorly controlled experiment. It's not nearly enough to "prove" anything.
How did he pick 2,000 calories? The video doesn't say. Maybe he ran some numbers to determine his estimated maintenance calories. (The online calculators are just rough estimates.) In any case, that number will be wildly different for different people. For example, an inactive 40-year-old five-foot-six-inch 150-pound female could gain weight on 2,000 calories a day.- He was provided a specific daily meal plan by his students. He didn't actually have to make any choices himself (other than to stick to the plan).
- No snacks were allowed. Ever. Not at home, not at work. Good luck with that.
- There were no meals anywhere else for six months. No dining out. No family meals. Again, good luck with that.
- The two previous points indicate the cornerstone of this plan: discipline. It may sound great (to some people) to eat at McDonald's every day, but only at McDonald's? Three meals a day every day? Eating only the foods allowed by the plan? Not great for anyone.
He may well be a very disciplined guy with excellent self-control, but the accountability was undoubtedly important. He had to do it for his students (particularly since it was his idea), and the school faculty was also watching. According to the video, as he continued, the whole town began watching. That's a lot of accountability. (We don't know if his becoming a paid "brand ambassador" for McDonald's offered any motivation.)- There were no measurements of body fat so we don't know how much of the weight loss was fat or how much was muscle. Since he wasn't doing any strength training, he surely lost muscle.
There are other considerations, but you get the idea.
That's not to say that fast food can't be part of a healthy diet. Of course it can. And calories count a lot (as if you didn't know). This "experiment" doesn't prove anything, no matter what McDonald's (or their ambassador) would like you to believe. There are lots of ways to eat healthy. The best way is the one that works for you.
Be seeing you.
-gary