Extract:
For longer than I can remember, experts have bandied around a maxim, as if taken from some secret book of indisputable fat-burning facts, that if you want to lose weight, don’t eat past 7 in the evening.
Hearing and reading this as often as I do, it doesn’t surprise me that repetition replaced truth. The explanation is convincing and when I was younger, I took for granted its validity because of the logic: metabolism drops, so feeding the body after 7pm sends calories straight to the gut (or waist, or thighs, or butt depending on who’s giving the advice and to what audience they give it).
As naked logic is not always convincing enough, the experts also add that digesting all that food before bed destroys the quality of sleep.
This is a load of crap. The explanation sounds reasonable, and in the absence of controlled research, I’d say it’s a method worth following. But we do have controlled research and it makes anyone look ignorant who claims or suggests that eating after 7 increases fat gain—lipogenesis for you terminology geeks. The facts just don’t match this simplistic logic.
Believe me, I’m the last person to admit that reading the research articles is fun, and many people read the abstract—the summary at the beginning of the article—and make conclusions based on the synopsis. You’ve got to read the whole article and the eating-after-seven rule exemplifies why. Many of the abstracts for these studies say, “It seems advisable that for maximum weight loss, a larger proportion of calories should be eaten early in the day,” and while this is true, there’s more to the story.
In the weight-loss studies, participants either front-loaded calories (ate most of their food before 3 pm and only small amounts later) or back-loaded (ate most of their calories in the evening, up until going to bed). The front-loading groups lost 20% more weight. Hence the conclusion to not eat much in the afternoon and 7pm fits with most people’s schedules, so, why not?
Diagram of a DEXA scanner.