Many runners take up the sport to lose weight. It’s no wonder, given that 70 percent of Americans are overweight or obese these days, while runners mostly occupy the other end of the spectrum. It seems clear that running should lead to weight loss.

And it often does. The stories of people who have taken up running and dropped 50 pounds, 100 pounds, even 150 pounds are legion. You could become one of them. But these are just stories—random anecdotes. When researchers explore the connection between exercise and weight loss, they almost always find a more nuanced picture.

First and most important, running will make you fitter and healthier even if you don’t reach your fantasy weight goal. Literally thousands of studies have proven this. Running and other consistent aerobic exercise lowers the risk of heart disease, diabetes, cancer, and high blood pressure—the major so-called lifestyle diseases. No wonder health experts argue that fitness is more important than fatness.

Second, running and walking are the best ways to keep off any pounds you lose. That’s a big deal, because short-term weight loss is relatively easy, but long-term weight loss maintenance is very difficult. Few achieve it.

Many who do succeed have shared their secrets with the National Weight Control Registry. Among their habits: eating breakfast, weighing themselves often, and walking or running an hour a day. Exercise keeps the pounds off.

But calorie cutting is more effective at producing the initial weight loss, according to most experts. They don’t care what diet you choose, so long as it’s one you can maintain for the rest of your life. Nutrition experts also endorse regular aerobic exercise for its many health benefits.

The two-pronged approach is one we can all agree upon. The best diet and exercise programs are the ones you can sustain not just for three months, or maybe six, but for the rest of your days. Optimal health must be a lifelong pursuit.

  

Eliminate sugary drinks: Runners tend to hydrate a lot, and too many of their favorite drinks include too much sugar. Even fruit juices are loaded with sugars, albeit natural ones. Substitute water for all calorie-laden drinks. It’s the easiest way to reduce your daily calorie intake, and lose weight, while ensuring that you also hydrate sufficiently.

  

Cut sweet, fatty foods like cakes and cookies: Every gram of fat adds nine calories to your total daily count versus just four calories each for carbs and protein. In addition, fats are less filling than the other two groups, and require fewer calories to assimilate fully. This digestive process, called the thermic effect of food, can “erase” as much as 30 percent of the proteins you eat, and 20 percent of the carbohydrates, but only 5 percent of fats.

Cut out all the sweet, fatty foods you can. No one achieves perfection in this department. We all enjoy a tasty-but-sinful treat on occasion, and that’s OK. Just keep these occasions to a minimum.

  

Aim for volume, not density: One of the most proven weight-loss methods is to increase the volume of your food while decreasing the calorie density. This system even has a name, Volumetrics. It was first proposed by Pennsylvania State University nutrition researcher Barbara J. Rolls, PhD.

Salads are low calorie but high volume because lettuce and other vegetables contain a lot of water and fiber. Add a little protein to the top of your salad—such as fish or chicken—and it becomes a complete meal. Avoid “high-energy-density” foods such as chips, french fries, ice cream, cookies, and the like.

  

Skip the burgers and pizza: Sad to say, but America’s favorite fast foods are also among the least healthy, and most likely to pack on pounds. Both burgers and pizza are high in salt and saturated fats. Far better to choose alternative meals.

Many pizza fans convince themselves that a little tomato sauce and a few veggie slices are enough to make pizza a healthful food. Unfortunately, that’s not the case. Even if you pile on extra veggies, you won’t change the basic equation much. Pizza ranks as the fifth most frequently eaten food in the country, and is hence a major contributor to the obesity crisis.