Does skipping breakfast make you fat or thin?
I should state my bias up front: I’m a big believer in the importance of breakfast, fully indoctrinated by my mother from a very young age. So when I saw this press release, my skepticism ramped up to full power. It describes a new study in Nutrition Journal (full text available here) that analyzed the diets of 280 obese and 100 normal weight subjects for 10 to 14 days, concluding that eater a bigger breakfast led to greater overall caloric intake for the day:
Therefore, overweight and obese subjects should consider the reduction of breakfast calories as a simple option to improve their daily energy balance.
Heresy! Or is it… I decided I should at least read the paper. It turns out this is, indeed, a long-running debate. The authors of the new study, from the Else-Kröner-Fresenius Center of Nutritional Medicine (in Munich, where compound nouns are a way of life), argue that previous studies have been guilty of what seems like a fairly obvious error in interpretation. These previous studies have found that the higher the proportion of your daily calories you get at breakfast, the lower your overall caloric intake is that day. But these results are skewed by days when people choose to have unusually small lunches and dinners, the new study argues.
The details of this statistical debate are fairly intricate — and not that interesting, actually. Because the strongest arguments for breakfast were never predicated on the theory that you’d eat less later. It’s the other side of the energy balance equation that’s more interesting. By taking in the calories at the start of the day, you’re getting them right when you need them, rather than later when your physical activity for the day is done. You’re also getting your body out of starvation mode so that you’ll choose healthier foods and not store everything as fat when you finally cave in and have some food.
So what are the long-term effects of skipping (or not skipping) breakfast? A study in December’s American Journal of Clinical Nutrition followed 2,184 Australian kids back in 1985, and then checked in again in 2004-2006. The study looked for the effects of skipping breakfast as a kid, an adult, both, or neither. The results:
[P]articipants who skipped breakfast in both childhood and adulthood had a larger waist circumference and higher fasting insulin, total cholesterol, and LDL cholesterol concentrations than did those who ate breakfast at both time points.
Now, you might say that the people who skipped breakfast also happened to be Very Bad People in other aspects of their health. That’s a fair point — though the researchers do at least try to account for the possibility that the breakfast-skippers were eating trash for the rest of the day:
Additional adjustments for diet quality and waist circumference attenuated the associations with cardiometabolic variables, but the differences remained significant.
If you’re still not convinced, consider this final salvo, from the European Journal of Clinical Nutrition in September. Researchers at King’s College London analyzed the breakfasts eaten by 60 kids, then gave them a battery of cognitive tests. Now, it’s old news that breakfast makes you smarter. The new wrinkle in this study is that they broke the data down into four groups depending on glycemic index (how quickly sugars will enter the bloodstream) and glycemic load (glycemic index times portion size). The results weren’t entirely straightforward, but the best option seemed to be a low-GI, high-GL breakfast — in others words, have a big breakfast but make sure it’s not just a bunch of sugar and refined cereal or bread.
Last point: this isn’t carte blanche to totally ravage the breakfast buffet. In the study that sparked this post, one of the foods that contributed most to breakfast calories was cake (51 cal for the obese group, 132 cal for the normal group!). I mean, come on! If the Else-Kröner-Fresenius folks are advocating skipping breakfast to lose weight, then I heartily disagree. But if they’re just suggesting that you should go easy on the cake and sausages, then yeah, that sounds like pretty good advice — at any meal.