Is six meals a day the secret to losing weight?
A lot of people believe that eating more frequently boosts your metabolism. I debunked this in the first year of the Nutrition Diva podcast, which was (can you believe it?) ten years ago. The research that I reviewed back in 2008 for my episode on Metabolism Myths simply didn’t support the notion that you could burn more calories simply by dividing your daily intake into smaller, more frequent meals.
But our understanding of human nutrition is constantly evolving and it’s always worth revisiting those stances in light of newer evidence. In The Abs Diet, author David Zinczenko claims that eating six meals a day will help you reveal that six-pack you’d like to flaunt. (Due to inflation, we now strive for an eight pack, but back then, an abdominal six-pack was considered sufficient.)
“You have to eat more if you want to lose more,” he writes, “[And] there’s science to support the fact that more meals work.” He then describes two specific studies to prove that eating more frequently will help you burn more fat.
What’s the Proof for Six Meals a Day?
One of these studies, dating from 2000, involved nationally-ranked, 15-year-old gymnasts and 26-year-old runners, all of whom were female. The study didn’t look at how often the women ate. Instead, it was looking at the difference between calories consumed and calories burned on an hourly basis. And they found that the athletes who replaced the calories they burned more quickly had less body fat than those who waited longer.
Remember: these are world class athletes. Their body fat percentages were all very low to be begin with. So the change in body fat was the difference between “very low” and “very very low.”
What this study really shows is that when you are training at the level of a world class athlete, you don’t want to delay your post-workout recovery meals. I’m really not sure, though, how relevant this is to Zinczenko’s audience.
The other study he cites, from 1996, involved 12 boxers who were put on extremely low calorie diets (just 1200 calories a day) for two weeks. Boxers will often crash diet before events in order to qualify for certain weight classes. In this study, six of the boxers divided their 1200 calories into two meals and the other six ate the same number of calories divided into six meals. Both groups lost a bunch of weight and, not surprisingly, a significant amount of lean muscle. That’s what happens when you lose weight too quickly. But the loss of muscle was a bit less in the group who ate more frequently.
What this study really shows is that when you are crash dieting, you’ll lose less muscle if you eat more frequently. But if your goal is a six pack (or any multiple thereof), you don’t want to be losing muscle. You want to be losing fat. Crash dieting is not recommended. So, again, I’m not sure this study is all that relevant to the claim or the audience.
How Does It Work for Real People?
But these are not the only studies out there to look at the relationship between meal frequency and weight loss or body composition. And some of the other studies I found might be a bit more applicable to you and me, and to most of those who are reading The Abs Diet.
In 2017, researchers analyzed data on more than 50,000 adults. This was data from the Adventist Health Study and involves a population that tends to be healthier than average. But they are not elite athletes. These subjects are also what we call “free living.” That means their meals were not being provided by researchers and they were not living in a research lab. They were living in their homes, working at their jobs, cooking their own food, and so on. Kind of like you and me. The researchers found that the people who ate more than three times a day weighed more than those who ate less frequently.