Grazing vs intermittent eating

We used to say, especially me, that grazing, like horses and little kids and probably everybody does, was better than starving all day and then gorging on a big dinner. We used to harp about the importance of breakfast, especially for kids, that usually results in at least two “square meals” a day. Now we have to preach the contrary. (There are obviously parallels between this article and the theme of our last column about yo-yo dieting.)

How long we live seems to be controllable by restricting calories and losing weight. But a new slightly less painful idea, that might be as good, is periods of fasting between eating.

To try and examine this question about grazing vs episodic meals some investigators showed that mice allowed to eat as much and as long as they wanted had more disease burden and shorter lives than mice fed for only 13 hours of the day and fasted for 11 hours. Mice fed only 3 hours a day ate very fast and lived even better and longer than that. These results were independent of dietary composition – calorie proportions from proteins, carbs and fat – and also independent from the effects of calorie restriction. “These health and survival benefits conferred by periods of extended daily fasting, independent of dietary composition, have major implications for human health and clinical applicability,” according to these investigators.

After obesity surgery when they make you a tiny stomach you kind of have to graze; you can’t eat very much at a time, and we all know that leads to big weight loss and improved health. But that’s very different. So set that aside.

Also you can graze on low calorie celery and so grazing is not the opposite of dieting.

Remember finally that periods of fasting does not necessarily result in weight loss and might not make weight loss any easier.

I read once that this is how African Pygmy tribes do it. They spend weeks stalking a giraffe and then trailing it after they wound it because they are not good at killing efficiently and then schlepping it home. Then they eat so much meat that they can hardly walk because they don’t have refrigerators to store the meat.

Maybe we should do like Pygmies and stop arguing about what you eat and start talking about how you eat. But maybe not necessarily for horses or kids or everybody. You have to be careful about fasting if you take insulin for example.

I don’t know how long Pygmies live. I’ll have to google that. Maybe we would all wind up smaller over all. Stay tuned.


2. Mitchell SJ et al. Daily Fasting Improves Health and Survival in Male Mice Independent of Diet Composition and Calories. Cell Metabolism. Available online Sept 6 2018.