Obesity and Weight Loss

Read about our research to help you make changes toward a healthier lifestyle.

The Low-Carbohydrate Approach for Weight Loss

The low-carbohydrate (“low-carb”) approach is not really a “diet” but a lifestyle; hence our use of the term “approach.” The emphasis with the low-carb approach is more on choosing healthful foods, and less on counting calories. If followed carefully, the low-carb approach will result in loss of fat, maintenance of muscle, and improved health (lower risk for heart disease and diabetes). The low-carb approach is easy, and a lot less work and worry than counting calories. It is also very effective, allowing individuals who “struggle with their weight” to finally lose weight and keep it off. The low-carb approach is not dangerous. Humans did not evolve to eat processed carbohydrates such as breakfast cereal and bread. We evolved to eat foods like meat, nuts, and vegetables. Thus, elimination of pasta, bread, & other processed carbs is not harmful. In fact, consumption of processed carbs has been linked to increased risk of heart disease and diabetes.

It is important to keep in mind that dietary fat is not harmful as long as dietary carb intake is low. However, the combination of high dietary fat and high carb has adverse health effects. Thus, it is critical to make a commitment to all aspects of the low carb approach. The low-carb approach is not meant to be temporary “fix;” it is a permanent lifestyle that you will want to continue for the rest of your life. Because you are overweight, you probably are very sensitive to the ability of carbs to cause weight gain. The dietary modifications you learn as part of the low-carb approach should be maintained for life. Thus, it is critical that you learn to use the tools we provide to develop a new eating pattern that you like and can stick with for the rest of your life.

IT’S THE INSULIN!

Carbohydrates increase insulin, which blocks your ability to burn fat of any kind, including dietary fat, and to lose body fat. If you find yourself reaching for a high-carb or sugary snack, remember: The insulin spike produced by that snack may block your ability to burn fat for an extended period. Paradoxically, it is excessive consumption of dietary carbohydrates (not fat) that, by stimulating insulin, promotes weight gain and obesity.

Calories and Carbohydrates

The low-carb approach does not emphasize counting calories or reducing calories. Diets that emphasize simply reducing calories, such as low-fat, low calorie diets, can cause your body to rebel by dropping its metabolic rate, thus sabotaging your attempts to lose weight. However, because you do not “need” carbs, you can safely reduce carbs without changing your metabolic rate. As long as you eat enough protein and fat-containing foods, your metabolism will not drop. In fact, evidence suggests that educing carbs may increase metabolism. However, food intake cannot be unlimited, even with the low-carb approach. If you are trying to lose weight, weight loss will be more rapid if you are careful to consume only the recommended number of servings of all food categories (protein, fat, and vegetable) each day. Your dietitian can help you develop the plan that is right for you.

The beauty of the low-carb approach is that you will not feel hungry. Fat- and protein–containing foods are very satisfying, and you are likely to find that you enjoy your new lifestyle. You will be losing weight without being hungry.

Carbs Equal Sugar

The key fact to learn and remember with the low-carb approach is that carbs are essentially “sugar,” and sugar causes the body to secrete the hormone insulin. Insulin causes the sugar to be burned as fuel or stored as glycogen. Insulin also, at the same time, causes fat to be stored and prevents the use of fat as a fuel. Habitual consumption of many carb-containing foods leads to an increase in insulin levels in the blood. When this occurs, the body reduces its use of fat as a fuel, and comes to depend on glucose (“sugar”). Eventually, the body fails to burn fat for a fuel, and relies entirely on burning glucose. At this point, most the fat eaten is stored as fat. You can think of this as a “one-way street” for fat-containing foods (cheese, meat fat, butter, oil, and many processed foods). Once they are eaten, they can only be stored as fat, and once stored, they can never be used for fuel. In this scenario, it is very difficult to lose weight, in particular, to lose fat. Individuals who have high insulin for genetic or other reasons are particularly sensitive to carbohydrates, and spontaneously lose more body weight when eating a carbohydrate-reduced (vs fat-reduced) diet.

Research Outcomes to Remember

In order to change the metabolism to allow fat to be mobilized and burned as fuel, insulin must be lowered. The best way to lower insulin is to avoid eating foods that cause insulin to be secreted; this means avoid eating carbs. The low-carbohydrate diet prescription we recommend can be found here. If you cut carbs out of your diet, after a few days, your insulin levels will drop, and you will start to burn fat and lose fat. You will see your waistline shrink.

However, if you eat a carb-containing food, this will cause insulin to go up, and you will be back where you started: unable to burn fat and lose weight, possibly for several days. It is important to remember that eating the carb-containing food is “bad” because it causes insulin to be secreted, and the insulin prevents fat loss.

Key Points

The low-carb approach is not a “diet;” it is a permanent lifestyle.
Carbs increase insulin; insulin blocks your ability to burn fat as a fuel. If your insulin is high, you cannot lose weight.
If you are overweight, you are sensitive to carbs. Not everyone is sensitive to carbs, but many people are.
Avoid problem foods that cause you to binge or crave carbs. Cravings will disappear if you stop eating carbs.
Eat fat = burn fat. Eat carbs = store fat.
There is no such thing as an “essential carbohydrate.” Humans did not evolve to eat processed grain or sugar.
The low-carb approach is not a crazy experiment; humans evolved to eat fat and protein. The crazy experiment was agriculture/processed carbohydrates, and it didn’t work.
Dietary fat is safe to eat; it is the combination of high-fat and high-carb that leads to weight gain, heart disease, and diabetes.
The low-carb approach is a high-fat diet, not a high-protein diet. Excess protein can be metabolized into sugar.
Dietary fat is good! You will not be hungry if you eat enough fat, your energy level will increase, and you will lose weight.

Frequently asked questions

Obesity & Weight Loss