A low-carb diet restricts your intake of foods high in carbohydrates, such as pasta, bread, starchy vegetables and sugar. Weight loss is one of the positive side effects of this type of diet, which emphasizes protein, healthy fats and watery, fibrous vegetables. Exactly how restrictive you have to be with your carb intake depends on your personal carb sensitivity, current carb intake, activity level and weight-loss goals.
Why Low-Carb to Lose Weight
Reducing your carbohydrate intake cuts out the source of many empty calories. No longer will you consume white bread, muffins, cookies, pastries, white rice and soda, for example. You'll most likely end up eating fewer calories, too.
Not only will you probably eat less on this meal plan, but you may not feel as hungry because low-carb diets are especially good at helping curb your appetite. Eating fewer carbs helps stabilize your blood sugar so you don't experience wild swings that activate cravings and cause you to overeat.
Carbohydrates also cause you to hold onto excess water weight. When you reduce your intake, some of that water flushes away, resulting in a lower body weight. So keep in mind that some of your initial weight loss on a low-carb diet probably isn't fat, just fluid.
Types of Low-Carb Diets
The standard nutrition recommendation from the Institute of Medicine is to get 45 to 65 percent of your daily calories from carbohydrates. For a basic 2,000-calorie diet, this amounts to between 225 and 325 grams of carbs per day. A moderate low-carb diet restricts you to between 100 and 150 grams of net carbs per day, while some low-carb diets permit just 50 to 100 grams of net carbs per day. A very-low-carb diet restricts you to 50 grams of net carbs per day or fewer. The initial "induction" phase of the Atkins diet is a very-low-carb diet in which you start with no more than 20 grams of net carbs daily.
A very-low-carb diet usually pushes you into a state of ketosis, in which your body burns fat more efficiently and produces chemicals called ketones to fuel your brain in the absence of carbs. A ketogenic diet features a high fat and moderate protein intake and is often accompanied by an uncomfortable phase-in period during which you experience side effects, including sagging energy, poor physical performance, headaches and nausea.
"Net" carbs are the ones that affect your blood sugar. You figure a food's net carb value by subtracting its grams of fiber from its total grams of carbohydrates.
What to Eat on Each Low-Carb Plan
All low-carb diets encourage you to avoid bread, pasta and sugary treats, which greatly increase your carb intake. You eat plenty of meats, poultry, fish, cheese, oils and leafy greens on any low-carb diet.
A moderate low-carb diet of 100 to 150 grams per day might include 1/2 cup of grains, such as brown rice or pearled barley, at two or three meals -- each has about 20 grams of net carbs per 1/2 cup. You could enjoy 1/4 to 1/2 cup of starchy vegetables, such as winter squash or carrots; one to two pieces of fresh fruit, such as one-half of an apple and a whole peach; and 1/4 cup of black or cannellini beans at meals, too. Moderate servings of healthy fats, such as an ounce of nuts or one-quarter of an avocado, are also allowed at most meals.
A 50- to 100-gram low-carb diet could include a serving of lower-carb fruit, such as 1/2 cup of fresh raspberries, with 3 grams of net carbs and 1/2 cup of grains at one meal daily. The rest of your carb intake comes from watery fibrous vegetables, including broccoli, cauliflower, eggplant, cucumbers, peppers and mushrooms. All are low in net carbs, with 1 to 2 grams total in each 1/2 cup. When these veggies are making up the bulk of your meals, however, their carbs do add up quickly to 50 to 100 grams. You'll seek out fat from low-carb sources, such as seeds and nuts as well as cooking oils and avocado.
A very-low-carb diet has you subsist mostly on animal protein, healthy fats and vegetables. Even your vegetable intake at each meal is restricted to keep your carb intake extremely low. Coconut oil, fatty fish, olive oil and modest servings of cheese contribute most of your fat as these items are low in carbs. You might have eggs and bacon for breakfast; a cheese stick and almonds as a snack; a burger patty with cheese and an egg for lunch; and chicken and vegetables stir-fried in coconut oil for dinner.
Which Low-Carb Diet Is Right for You?
It may take some experimentation to determine which low-carb diet is right for you. If you're considerably overweight or obese and need to lose weight desperately, a very-low-carb, or ketogenic, diet might be right for you. Usually, this diet yields pretty dramatic weight loss, but it isn't without risks and side effects, so you should consult with your doctor before starting.
When you first start eating low-carb, a moderately low-carb diet of between 100 and 150 grams may be enough to initiate weight loss. A moderate low-carb diet may not feel too restrictive and still provides you with energy for exercise and enough carbs to ward off the unpleasant symptoms that can accompany extremely low-carb plans. Especially active individuals may find this moderate-carb reduction best supports their lifestyle and weight-loss goals.
If you reach a weight-loss plateau or fail to lose pounds on a moderate low-carb diet, you may need to restrict your intake to 50 to 100 grams to experience further loss. Some people may need to reduce their daily intake to less than 50 grams or even 20 grams for a few weeks to get pounds to budge. If you need help planning a low-carb diet, get assistance from a registered dietitian.
- American Journal of Clinical Nutrition: Low-Carbohydrate Nutrition and Metabolism
- Institute of Medicine: Dietary Reference Intakes for Energy, Carbohydrate, Fiber, Fat, Fatty Acids, Cholesterol, Protein and Amino Acids
- Authority Nutrition: The Ketogenic Diet 101: A Detailed Beginner’s Guide
- Atkins: Carb Counter
- Authority Nutrition: Top 15 Reasons You Are Not Losing Weight on a Low-Carb Diet
- Authority Nutrition: How Many Carbs Should You Eat per Day to Lose Weight?
- Atkins.com: Atkins 20™