How can a low-carb diet affect a teen's weight?

Laura Motosko, MSEd, RD
Nutrition & Dietetics

A low-carb diet which may involve excluding grains, starchy vegetables, fruits, dairy and sugar can promote short term and sometimes unhealthy weight loss in a teen. I recommend for a teen who would like to maintain a healthy weight to eat a nutrient dense diet of healthy fats such as olive oil, avocados and nuts, with whole grain carbohydrates, and protein in dairy, lean meats, and legumes to promote building, calorie burning, lean muscle mass. Avoid complex carbohydrates such as those found in candy, soft drinks, chips and other refined bread carbohydrates.

Daphne Oz
Health Education
Low-carb diets, such as the famous Atkins plan, initially help you to lose weight because you are limiting the amount of glucose (a simple carb) entering your body. Whenever you eat carbs, your digestive system breaks up larger molecules, such as starch and fiber, into simpler sugars, or glucose; this sugar circulates in your bloodstream, and is called blood sugar. It is transported to all the different cells in your body, where it is either immediately used for cell functions or stored as glycogen in your muscles and liver.

When all the glucose in your bloodstream is depleted, your body begins to break down glycogen, since it is easier to convert for fuel than fat or protein. But your body stores only so much glycogen (about enough for one strenuous workout). When this store is finished, it needs to be replenished by eating carbs -- which can't happen if you aren't eating any. In addition, with every molecule of glycogen that is released from your muscles for energy, three molecules of water are also released. Loss of this "water weight" accounts for a lot of that initial weight loss you see at the beginning of low-carb diets. Losing glycogen stores and water will cause your muscles to shrink (lowering your basal metabolism, the number of calories you burn when you're doing nothing) so that, while it may seem as if you are losing a tremendous amount of weight in the first weeks of a no-carb diet, it's important to keep in mind that you are losing muscle weight, not fat, and that, long term, your ability to burn calories is declining.
The Dorm Room Diet: The 10-Step Program for Creating a Healthy Lifestyle Plan That Really Works

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The Dorm Room Diet: The 10-Step Program for Creating a Healthy Lifestyle Plan That Really Works

The 10-Step Program for Creating a Healthy Lifestyle Plan That Really WorksThe Dorm Room DietRevised and Updated EditionFiguring out how to eat right and stay healthy on your own can be hard! Here is...
Melinda Johnson
Nutrition & Dietetics

The low-carb diet is typically considered a fad diet by most health professionals. Fad diets usually produce some weight loss in the short term - the problem is that most people re-gain that weight, plus more! There are also studies that indicate when kids and teens engage in fad dieting, they develop a poor relationship with food and a negative body image. In the end, the fad diet fails them in more ways than one. 

The teen years are a perfect time to begin learning self-care that will help the teen grow into the adult weight they were meant to be. This means learning how to prepare simple, healthy meals,  how to fit in enjoyable exercise, and how to make sure they are getting enough sleep. These are also great years to learn what kind of habits are contributing to too much weight - this might be a daily soda habit, or eating out of boredom. These are the truly meaningful lifestyle changes that will help the teen become healthier for good.

Cassie Vanderwall
Nutrition & Dietetics

Low-carb diets can promote weight loss for several reasons:

  • Carbohydrates help to "hydrate" the body, so when we eat fewer carbs the body loses water.
  • Carbohydrates often are 50% of what we eat, so when we eat less sources of carbohydrates we tend to eat less.
  • Lower carbohydrate diets lead to high fat and higher protein diets which are two energy sources that take longer to digest. Since the process takes longer people often stay full longer and therefore eat less.


Cindy Guirino
Nutrition & Dietetics

Teenagers that follow a diet low in carbohydrates will have an energy drain.  Carbohydrates main job is to provide our bodies with energy.  Did you know that your brain and central nervous system rely only on the carbohydrate (glucose)? 

Initially, when you eat an inadequate amount of carbohydrate weight loss will show up on the scale, this is because when you metabolize carbohydrates, water is involved.  Less carbs....less water = weight loss.  This is not body fat weight loss which is really what people strive for.

Judy Caplan
Nutrition & Dietetics

Teens are like bees, they gravitate to sweets! Too many fried and processed foods are high in carbs and can add unwanted pounds to a teenage body. Reducing carbs can cause teens to drop weight or just stop gaining weight. Carbs are also found in fruits and vegetables, beans, and whole grains. These are the best carbs for teens. Teens need carbs for energy but do not need to overload on the more refined carbs.

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Important: This content reflects information from various individuals and organizations and may offer alternative or opposing points of view. It should not be used for medical advice, diagnosis or treatment. As always, you should consult with your healthcare provider about your specific health needs.