LowCarb diet: can it help you lose weight?
Could a low carb diet give you an advantage in losing weight? Can it help you to reduce your weight permanently? Here we explain what you need to know about the LowCarb diet.
A LowCarb diet limits carbohydrates - such as those found in grains, starchy vegetables and fruits - and emphasizes foods high in protein and fat. There are many types of lowcarb diets. Each diet has different restrictions on the types and amounts of carbohydrates you can eat.
A LowCarb diet is generally used to lose weight. Some LowCarb diets may have health benefits beyond weight loss, such as reducing risk factors associated with type 2 diabetes and metabolic syndrome.
Why you should follow a low-carb diet
Maybe that's why you're choosing a low-carb diet:
- Want a diet that restricts certain carbohydrates to help you lose weight
- You want to change your eating habits overall
- Enjoy the types and amounts of foods included in low-carbohydrate diets
- Talk to your doctor before starting a weight loss diet, especially if you have health problems like diabetes or heart disease.
As the name implies, a low-carb diet restricts the type and amount of carbohydrates you eat. Carbohydrates are a type of calorie-providing macronutrient found in many foods and beverages.
Carbohydrates can be simple or complex. They can be further classified as simply refined (table sugar), simply natural (lactose in milk and fructose in fruit), complex refined (white flour), and complex natural (whole grains or beans).
Common sources of naturally occurring carbohydrates are
- Legumes (beans, lentils, peas)
Food manufacturers also add refined carbohydrates in the form of sugar or white flour to processed foods. Examples of foods that contain refined carbohydrates include white breads and pastas, cookies, cakes, candies, and sugar-sweetened sodas and beverages.
Your body uses carbohydrates as its main source of fuel. Complex carbohydrates (starches) are broken down into simple sugars during digestion. They are then absorbed into the bloodstream, where they are called blood sugar (glucose). In general, natural complex carbohydrates are digested more slowly and have less effect on blood sugar. Natural complex carbohydrates provide mass and serve other body functions beyond fuel.
Rising blood sugar levels cause the body to release insulin. Insulin helps glucose enter the body's cells. Some glucose is used by the body as an energy source needed for all activities, whether jogging or simply breathing. Extra glucose is usually stored in your liver, muscles and other cells for later use or converted to fat.
The idea behind the low-carb diet is that reducing carbohydrates lowers insulin levels, which causes the body to burn stored fat for energy and ultimately leads to weight loss.
Typical foods for a low carbohydrate diet
In general, a low-carb diet focuses on proteins, including meat, poultry, fish and eggs, as well as some non-starchy vegetables. A low-carbohydrate diet excludes or restricts most grains, legumes, fruits, breads, sweets, pasta, and starchy vegetables, and sometimes nuts and seeds. Some low-carbohydrate diet plans allow small amounts of certain fruits, vegetables, and whole grains.
A daily limit of 20 to 60 grams of carbohydrates is typical for a low-carbohydrate diet. These amounts of carbohydrates provide 80 to 240 calories. Some low-carbohydrate diets severely restrict carbohydrates during the initial phase of the diet and then gradually increase the number of carbohydrates allowed.
In contrast, the Dietary Guidelines for Americans recommend that carbohydrates make up 45 to 65 percent of total daily caloric intake. So if you're eating 2,000 calories a day, you need to eat between 900 and 1,300 calories a day from carbohydrates.
Most people can lose weight by restricting the number of calories they consume and increasing their level of physical activity. To lose 1 to 1.5 pounds (0.5 to 0.7 kilograms) per week, you need to reduce your daily calories by 500 to 750 calories.
Low-carbohydrate diets, especially very low-carbohydrate diets, may result in greater short-term weight loss than low-fat diets. However, most studies have found that the benefits of low-carbohydrate diets are not great after 12 or 24 months. A 2015 review found that a high-protein, low-carbohydrate diet may provide a slight benefit in terms of weight loss and fat mass loss compared with a regular protein diet.
Reducing calories and carbohydrates may not be the only reason for weight loss. Some studies show that you can lose some weight if the extra protein and fat make you feel fuller longer, which helps you eat less.
Other health benefits
A low-carb diet can help prevent or improve serious health conditions such as metabolic syndrome, diabetes, high blood pressure, and cardiovascular disease. In fact, almost any diet that helps you lose excess weight can reduce or even reverse risk factors for cardiovascular disease and diabetes. Most weight-loss diets - not just low-carbohydrate diets - can improve blood cholesterol or blood sugar levels, at least temporarily.
A low-carbohydrate diet may improve HDL cholesterol and triglyceride levels slightly more than a low-carbohydrate diet. This may be due not only to how many carbohydrates you eat, but also to the quality of the other foods you eat. Lean protein (fish, poultry, legumes), healthy fats (monounsaturated and polyunsaturated) and unprocessed carbohydrates - such as whole grains, legumes, vegetables, fruits and low-fat dairy - are generally healthier choices.
A report by the American Heart Association, the American College of Cardiology, and the Obesity Society concluded that there is insufficient evidence to determine whether most low-carbohydrate diets provide heart-healthy benefits.
If you suddenly and drastically reduce carbohydrates, it can have a number of temporary health effects:
- Bad breath
- Muscle cramps
- skin rash
- constipation or diarrhea
In addition, some diets restrict carbohydrate intake so severely that they can lead to long-term vitamin or mineral deficiencies, bone loss, gastrointestinal disorders, and increase the risk of various chronic diseases.
Because low-carbohydrate diets may not provide the nutrients you need, these diets are not recommended as a weight loss method for preschool and school-age children. Your growing body needs the nutrients found in whole grains, fruits and vegetables.
Limiting carbohydrates to less than 20 grams (0.7 ounces) per day can create a process called ketosis. Ketosis occurs when you don't have enough sugar (glucose) available as an energy source, so your body breaks down stored fat and ketones build up in your body. Side effects of ketosis can include nausea, headaches, mental and physical fatigue, and bad breath.
It's not clear what the potential long-term health risks of a low-carbohydrate diet may be, as most research studies have lasted less than a year. Some health experts believe that your risk of heart disease or certain cancers increases if you eat large amounts of fat and protein from animal sources.
If you're eating a low-carb diet that includes more fat and possibly more protein, it's important to choose foods with healthy unsaturated fats and healthy proteins. Limit foods that contain saturated and trans fats, such as meats, high-fat dairy products and processed crackers and pastries.
Always consult your healthcare provider to ensure that the information displayed on this page applies to your personal circumstances.