Our great-grandparents didn’t have any trouble figuring out when to eat. They sat down at regular intervals during the day to consume predictable meals. There really wasn’t any alternative. They had dozens of jobs to perform around the farm, in the fields, and with the animals.

A few years later, many had transitioned to the factory floor, which demanded constant physical labor. No one carried around plastic bags full of processed, prewrapped convenience snacks to munch on constantly. A meal was a serious, sit-down affair: breakfast (a big one), lunch, dinner. Following this rigid schedule, our great-grandparents were notably leaner and stronger than nearly all of their descendants fifty to seventy years later—you and me.

Nowadays we snack more or less constantly throughout the day, while also spending most of our time in a car, chair, or sofa. The result—gradual weight gain—couldn’t be more predictable.

In an attempt to break this pernicious cycle, nutritionists and others have investigated various meal-timing strategies. It turns out, no surprise, that regular meals on a regular schedule are a good thing, as are gaps between meals without snacking. Consistent movement during the day stimulates muscle, and helps the body burn calories. Sitting most of the day, on the other hand, turns those calories into fat.

We have long been told that breakfast is the day’s most important meal, and much research supports the role of regular breakfast consumption. One recent study showed that those who eat breakfast cereal with milk every morning are 31 percent less likely to be overweight or obese than those who skip breakfast.

The protein in milk may be the key. Protein is the nutrient that has disappeared from many breakfasts, replaced by processed, high-carb “ready to go” foods too often consumed in the car or at a desk. In early 2017 the American Heart Association released a comprehensive twenty-seven-page statement on meal timing and frequency. One of its strongest recommendations was to eat a healthy breakfast including quality proteins.

  

Don’t graze constantly: The idea that one should snack on foods every couple of hours throughout the day has long been a popular one. Proponents have claimed that it will keep you energized and prevent big calorie splurges at mealtimes, thus curtailing weight gain. However, research has failed to support this claim.

Instead, grazing provides too many opportunities to eat, so it leads to weight gain rather than weight loss. You’ll do better to focus on regular, healthy meals. If you do get hungry for the occasional between-meal snack, be prepared. Have a handful of nuts nearby, or a yogurt, or whole fruit. Try to avoid the processed foods in the nearby convenience store or vending machine.

  

Stop eating after dinnertime: Many of us recognize the trap of late-evening food consumption. There are just so many possibilities, whether you’re enjoying social time with friends at a restaurant or bar, or relaxing at home while watching your favorite TV shows. Too often, we crave evening desserts laden with fats and sugars.

The night-eating routine leads to almost certain weight gain and related health concerns. Men who wake up at night to raid the refrigerator have a 55 percent increased risk of heart disease. On the other hand, one study showed that subjects who moved three hundred calories a day from dinner to breakfast (without changing their total daily intake) managed a substantial weight loss. The American Heart Association statement recommends that we eat during fewer hours each day, and give our bodies an ample overnight “fast” for the important metabolic processes that take place at night.

  

Try intermittent fasting: Somewhat to my surprise, the American Heart Association has also found preliminary but promising results for intermittent fasting. The most popular of these diets involves eating substantially less than normal two days a week, or every other day. Early results show that subjects don’t consume enough calories during their eating days to make up for the noneating days. Since they therefore consume fewer total calories per week, they gradually lose weight.

For runners this pattern has a familiar ring to it. We also train in intervals, usually referring to them as “hard” days and “easy” days. While I haven’t seen any studies on combined eating-and-training patterns, I can imagine that they would prove complementary. Runners could eat more on hard days when they need the energy, and less on recovery days when they are not exercising so vigorously.