Skip to content

The 'Why' Factor in Weight Loss

Science shows it's a head game, and motivation really matters

A mother and daughter, both African American walk down stairs outside as they exercise

Sarah Casillas/Getty Images

En español | Research shows there isn't one best way to lose weight. Some people shed pounds by counting calories, while others find success when they switch to a low-carb, vegan or paleo diet.

A meta-analysis of different weight-loss programs published in the Journal of the American Medical Association, for example, found that no one program was significantly better than the others. Instead, success correlated with how motivated people were to stick with the program of their choice.

"Most people know how to lose weight — you eat less or change how you eat, and then you burn more calories,” says Sofia Rydin-Gray, director of behavioral health at the Duke Diet and Fitness Center in Durham, N.C. “But because we are human beings, it's not that simple. There are psychological variables — we have feelings, thoughts and self-limiting beliefs that make it harder – and that's where motivation comes in.”

Obesity researchers have been working hard to figure out what helps some people stay true to their desire to lose weight while others flame out. The National Weight Control Registry, a list of more than 10,000 people from across the country who have lost at least 30 pounds and kept it off for more than a year, provides some clues, says registry coinvestigator Graham Thomas, an associate professor of psychiatry at the Brown Albert Medical School.

Thomas says very few people on the registry said they were motivated to lose weight because they wanted to look better. Instead, their reasons tended to go deeper, with many saying they were motivated by specific health concerns.

As you embark on your own journey to eat better and get healthier, here are some science-based strategies to help you find, and stick with, your weight-loss goals:

Find your “why"

The more you link your weight loss to your own values, the more success you are likely to have, says Gary D. Foster, a clinical psychologist who is the chief science officer at WW (formerly Weight Watchers). He recommends thinking deeply about why you want to lose weight. “The more specific you can get, the better,” he says. For example, he notes, “If your answer is that you want to be healthier, ask yourself why you want to be healthier." If your answer is that you want to look better, he suggests going deeper. Will it make you more comfortable in social situations? Will it help your confidence? “You want to get to that fundamental value that can serve as your motivational anchor."

For expert tips to help feel your best, get AARP’s monthly Health newsletter.

Be realistic

Setting unattainable goals can lead to feelings of frustration that may cause you to give up. In one study of women enrolled at weight-loss centers, for instance, those who set the biggest weight-loss goals were also the most likely to drop out. One to two pounds a week is a reasonable goal for most, experts say. Foster also recommends being realistic about your diet, because if you set too many restrictions, you will eventually overindulge. “It's very common for people to say things like, ‘I'm going to give up ice cream.’ That will last a few hours, or a few days if you're lucky,” Foster says. “That's not real life.” Instead, allow yourself to enjoy your favorite foods in moderation. Maybe you reward yourself with a small bowl of ice cream if you have a good week.

Break it down

Research shows that you're more likely to reach a goal if you break it into a series of more manageable steps. The boost in confidence you get each time you reach a subgoal will help you stay motivated. David Creel, a psychologist at Cleveland Clinic, recommends setting your bite-size goals around behaviors you can control. So instead of aiming to lose a certain number of pounds in a week, consider goals such as “I'm not going to eat after 7 p.m.,” “I'm going to take a walk five days a week,” or “I'm going to eat five servings of fruits and vegetables a day."

Contingency plan

Most people on the National Weight Control Registry failed a few times before they found long-term success. Try to remember that everyone has lapses. Research shows what's important is not to beat yourself up too much about it. “If you say to yourself, ‘I'm a failure. I'm never going to be able to lose this weight,’ you're going to give up and eat to make yourself feel better,” Rydin-Gray says. Instead, think about what happened and how you can learn from it, and then do something intentional right away to get back on track.