Eating breakfast won’t help you lose weight, but skipping it might not either – Harvard Health Blog
Yet another study has dispelled the popular “you have to eat breakfast” myth, and I’m thrilled. The breakfast cereal aisle is the most nutritionally horrifying area of the supermarket, crawling with sugary carbs in all shapes and flavors, all disguised as health food.
It’s true — eating breakfast is not associated with eating less nor with weight loss, which begs the question: can skipping breakfast help with weight loss?
What does research tell us about eating breakfast?
A plethora of intermittent fasting studies suggest that extending the overnight fast is indeed associated with weight loss, but also more importantly, with improved metabolism. Overnight fasting of at least 16 hours (which really isn’t that extended) allows blood sugar and insulin levels to decrease, so that fat stores can be used for energy. This makes physiologic and logical sense: Our bodies can’t burn fat if we keep filling it with fuel. The idea that having a meal first thing in the morning revs up the metabolism isn’t based in reality.
So where did the “breakfast is good for you” myth come from? Wasn’t it based on research? Yes, but it was not the right kind of research. Observational studies produce interesting observations, and that is all. At the population level, people who regularly consume breakfast also tend to be a healthier weight. That doesn’t mean that breakfast has anything to do with it. It may be that people who regularly consume breakfast also tend to have daytime schedules (no night shifts), or higher socioeconomic status (can afford breakfast), or generally more consistent habits than those who don’t. These are all more important variables associated with healthier weight, and observational studies don’t reveal any of that.
What do the strongest studies say?
So how do you properly study the effect of eating breakfast (or not) on weight? You’d want to conduct a randomized controlled trial (RCT) evenly dividing participants into breakfast vs. no-breakfast groups, and then measure specific outcomes, like daily calorie intake and weight. RCTs are experiments where you can control for confounding variables, and thus feel more confident about drawing conclusions. (Having said that, RCTs can have other issues, and we’ll go into that.)
Researchers from Melbourne, Australia looked at a number of RCTs on breakfast and weight and/or total daily energy intake, and pooled the results. They found 13 studies in all that met their criteria: they had to define breakfast content and timing, and had to have been conducted in high-income countries (to be more comparable).
- Seven studies looked at the effects of breakfast on weight change, and after an average study length of seven weeks, participants who ate breakfast gained 1.2 pounds compared to those who didn’t. This was true for both normal and overweight people.
- Ten studies looked at the effects of breakfast on total daily calorie intake, and after an average study length of two weeks, participants who ate breakfast consumed 260 calories more than those who didn’t. These results help debunk the notion that skipping breakfast will cause people to binge later. While plenty of studies suggest that eating close to bedtime is associated with obesity, this has nothing to do with breakfast.
Are there flaws in these studies?
The authors do point out that the RCTs had flaws. Participants knew what experimental group they were in. The studies used various groups (college students, hospital staff, general public); featured different foods (crisped rice, wheat flakes, oatmeal); and had widely varying follow-up times. The RCT comparing a high-protein, high-fiber breakfast with nothing has yet to be conducted.
Still, in the end, the authors conclude: “While breakfast has been advocated as the most important meal of the day in the media since 1917, there is a paucity of evidence to support breakfast consumption as a strategy to achieve weight loss, including in adults with overweight or obesity.”
What’s the bottom line on eating breakfast?
Having said all this, if you love love love your breakfast, and you’re healthy, then enjoy! If you’re struggling with a metabolic medical problem, consider a breakfast of water, tea, or coffee and then have a healthy lunch. Or, at the very least, try not to eat close to bedtime. Whatever your preferred schedule, try to stretch out the time between meals, and give your body a chance to burn fat. Your metabolism will thank you!
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