Exercise or Diet?

Q: I want to lose weight in the new year. I’m thinking of joining a gym and starting a regular exercise program to drop the extra pounds. Is exercise really more important for losing weight than what I eat? –Carol S., Salt Lake City

No, it’s not. Scientific evidence supports that changing your diet is the most important factor-and much more important than physical activity-in whether yo

u lose unwanted weight. Furthermore, whether you believe that or not appears to have a big bearing on controlling your weight.

Virtually all of us have heard that we can eat anything we want “in moderation” and burn off the extra calories through exercise to lose or maintain our weight. But the 2014 documentary Fed Up says, “Everything we’ve been told about food and exercise for the past 30 years is dead wrong.” The idea that we can exercise away excess weight is a message food manufacturers have pushed-health professionals, the media, and television shows have picked up on it, and we now accept it as fact. But following that strategy isn’t working for people who need to lose weight, and that’s why the United States and other countries are not winning the battle of the bulge.

Fed Up explains that the food industry adds high-calorie, high-carbohydrate, nutrient-void sugar to 80 percent of the foods found in a typical supermarket and wants us to believe that we can eat and drink the sugar-rich foods and beverages it creates without gaining weight or developing any health problems. Consequently, many people who want to lose weight ignore the quality of the food and drinks they consume and simply vow to hit the gym. When this doesn’t work, all too frequently, they give up.

The Scoop on Exercise

Exercise offers numerous benefits, such as keeping heart disease at bay, boosting your mood, and improving sleep. But repeated studies have shown that many people who begin an exercise program lose little or no weight. Some, especially those who do fiery spurts of vigorous exercise, gain weight. Sure, exercise burns calories, but it also can stimulate hunger and cause us to eat more calories-effectively canceling any weight-loss benefits.

Research indicates that people who exercise strenuously eat more calories throughout the day than those who don’t. Whether that’s because exercise makes people hungry, or because people are more tired, have less self-control, or want to reward themselves after working out, it’s common for people to eat both more and junkier foods after going to the gym. This phenomenon is so common, it’s something TIME magazine wrote about in a 2009 article entitled “Why Exercise Won’t Make You Thin.”

What You Believe is Important

Your everyday beliefs about whether exercise or diet is the key to weight loss guide your actions and the actual likelihood of being overweight, according to six studies published in Psychological Science. In the studies, researchers asked a total of more than 1,200 people in the U.S. and four other countries about the main factor that makes people overweight. They found that those who said it’s most important to exercise to prevent obesity had a higher body mass index (BMI)-in other words, were more likely to be overweight-than people who said eating right was the key. In two studies, when researchers offered participants unlimited chocolate, those who said they think staying active is the key to a healthy weight ate more.

So, if you’re serious about losing weight effectively this year, restructure your beliefs. Buck the frenetic exercise trend and focus on what you eat. That’s the part of the obesity and overweight problem nearly everyone has missed.

Try a Sugar-Free Challenge

If you don’t know how to change your diet to lose weight, a good place to start is by trying a Sugar-Free Challenge as advocated in the documentary Fed Up. Avoid all foods with added sugars and artificial sweeteners for 10 days. Doing that is tougher than it sounds. Sugar is commonplace in foods, and research suggests it’s addictive.

If you’re like many Americans, when you cut sugar out of your diet, you’ll likely experience symptoms of withdrawal, such as crankiness or lethargy, at first. However, if you avoid all forms of added sugar, you’ll also likely lose weight without any change in physical activity, showing you firsthand the importance of diet over exercise.