By David Blyweiss, M.D.

It’s hard to believe that 2009 has come and gone—and here we are in 2010. If you’re like me, I always think of the New Year as the perfect time for a fresh start. For many, that means a renewed commitment to losing that excess weight.

Anytime there’s a discussion about diet and weight loss, the topic of carbs inevitably comes up. Indeed, the amount of carbohydrates you should eat in order to achieve a healthy weight is a very hot topic these days.Should you eat a low-carb diet or a high-carb diet in order to win the battle of the bulge? There is little consensus among the experts on the perfect mix of carbs, protein and fat for long-term weight loss. But, when it comes to the type of carbohydrates that people should eat to lose weight, everyone agrees that simple carbs are bad news.

Most of the people I run across who are overweight routinely eat refined carbs like white bread, semolina pasta, sweets and processed chips, cookies and crackers. Not only do these foods offer little nutrition, highly refined simple carbs quickly raise blood sugar levels—a scenario that sets you up for overeating. These foods may even be addictive. At least that’s what the Refined Food Addiction Research Foundation thinks. In fact, they say that an addiction to refined carbohydrates is not unlike being hooked on tobacco or alcohol!

But not all carbs are bad for you. In fact, there are many healthy carbs. Many foods linked with weight loss—whole grains, fruits and vegetables—contain carbs. Studies have linked a higher intake of fruits and vegetables with lower rates of obesity. Researchers have also discovered that diets low in whole grains, fiber, fruits and vegetables, and high in refined carbohydrates and trans fats are linked with obesity. So, it seems as if the key isn’t avoiding all carbs, but knowing which ones to include in your diet.

This was the emphasis of a new study in the The Journal of the American Dietetic Association. Scientists from the University of South Carolina, University of Saskatchewan in Canada, McMaster University in Ontario, Canada, and the United Arab Emirates University investigated the relationship between the amount and type of carbs routinely eaten and weight in 4,451 healthy adults who participated in the Canadian Community Health Survey.

The participants’ diets were assessed based on a 24-hour recall of all of the foods and beverages they consumed. Variables like age, sex, physical activity, income, education level and total calorie intake were also taken into account. After crunching all of the data, the researchers found that obesity was lowest among people who ate 47 to 64 percent of their calories from carbohydrates—which falls right in line with the current USDA Dietary Guidelines. The slimmer participants consumed more fruit, vegetables and fiber, and less saturated fat. They also reported being more physically active than those who consumed fewer healthy carbs.

The researchers stressed that the bottom line for weight gain is that it occurs as a result of eating more calories than the body requires, which also can be impacted by genes and the environment. While scientists have much more to learn about the complicated field of obesity and dietary patterns, the best advice I can give you for eating to lose weight is simple: Eat more whole, unrefined plant foods and less processed foods and unhealthy fats—and get out there and exercise.

References:

Ifland JR. Refined food addiction: a classic substance use disorder. Medical Hypotheses. 2009;72:518-526.

Kristensen M. Wholegrain vs. refined wheat bread and pasta. Effect on postprandial glycemia, appetite, and subsequent ad libitum energy intake in young healthy adults. Appetite. 2009 Oct 27. [Epub ahead of print]

Merchant AT. Carbohydrate intake and overweight and obesity among healthy adults.

Journal of the American Dietetic Association. 2009;109: 1165-1172