When I began running more than fifty years ago, I tried to avoid fatty foods as much as possible. This was the era when the American Heart Association and government nutrition sources were pushing a low-fat diet. Everyone believed it was the best way to avoid heart disease. Since my grandfather had had a heart attack in his fifties, and my father had too much belly fat, I wanted to avoid a disease-causing diet. I didn’t like the look of my genetics.

But I had an even stronger reason for avoiding fatty foods: The best runners seemed to be the skinniest. Even at a time when East Africans hadn’t yet climbed to the top of the marathon ladder, I could see that the guys who won big races were often the thinnest. And the ones behind were taller, wider, heavier. I wanted to win, so I forced myself onto a strict low-fat diet.

I became a vegetarian, I drank skim milk, I avoided eggs, and I kept a distance from junk foods. Not that I was perfect. No, I enjoyed ice cream too much for that, not to mention the German chocolate cake that my mother always baked on my birthday and other special occasions. But these were rare indulgences. The rest of the time I toed the line and avoided high-fat foods. You could tell that with one look at me. The day I won the Boston Marathon, I stood on the start line at six feet and 138 pounds.

No doubt I won Boston because I was one of the best-trained athletes in the field. The previous two years, I had run more than 100 miles a week almost every single week. But at the time I also believed I’d won because I was among the skinniest guys on the line.

I didn’t change my mind about low-fat eating for several decades. But in the early 2000s, I began to get the message. I learned that the early studies linking dietary fats to heart disease had probably been flawed, and the results overstated. No, that didn’t mean I could have chocolate cake and ice cream every night. But, yes, it was time for a closer look at fatty foods.

Many of them were in fact scrumptious, 100 percent natural, and health enhancing. I started eating eggs again for the first time in decades, switched to extra virgin olive oil, regularly bought avocados (which thrilled my Latina wife), and increased my nut consumption. My weight stayed the same, my cholesterol profile improved, and I enjoyed my meals more.

  

Avoid certain fats: I still try to limit my consumption of the most highly saturated fats such as full-fat dairy products, especially those that are fizzed, mixed, and whirred into concoctions that are also high in sugar. Some folks have decided that all fats have been excessively demonized, even the saturated fats. I’m not one of them. I still avoid palm and coconut oils because of their high saturated-fat content. On the other hand, I love and often eat avocados, which are high in monounsaturated fats, generally thought to be heart-healthy. For the same reason, I use olive oil (also high in monounsaturated fats) as my preferred salad dressing.

Because they are often high in saturated fat, I don’t eat red meats. If I did, I would look for meats from free-range animals that haven’t been raised on hormones. And I’d trim away as much fat as possible.

  

Seek out omega-3 fats: Populations that include regular fish consumption as a diet mainstay often have impressive records for health and longevity. Many nutritionists and epidemiologists believe this is due to the high omega-3 fatty acid content of some fish, particularly deepwater fish like salmon and tuna.

In addition to possibly conferring heart health benefits, omega-3 fats are linked with lower rates of depression. Runners will also appreciate their ability to decrease inflammation such as that associated with joint pain. You need only a few servings a week, and a high-quality fish oil supplement might help you get there (though supplements rarely match the benefits of real food).

  

Add more nuts to your diet: After I began eating more nuts in my midfifties, two rather remarkable things happened. First, I noticed that I was no longer hungry all day. As a result it was easier to cut back on the large rice and pasta dishes I craved at dinner.

Even better, my blood cholesterol profile changed substantially. My “good” (HDL) cholesterol almost doubled, while my “bad” (LDL) cholesterol plunged. I’ve been eating more nuts ever since, with continued happy results.