Diet trends come and go with some best left in the past (remember the grapefruit diet?). Today low-carb eating plans are soaring in popularity for those looking to lose weight. The Whole30, South Beach, Atkins, keto, and paleo are just a few on the scene.
A low-carb diet limits carbohydrates (fruit, grains, and starchy vegetables). The amount and type of carbs allowed depends on the diet.
In a healthy low-carb meal, three-quarters of the plate is filled with low-carbohydrate vegetables and the rest with 3 to 4 ounces of protein, according to David Perlmutter, MD, author of The Grain Brain Whole Life Plan ($28, Little, Brown and Company, 2016).
Low-carb vegetables include Swiss chard, bok choy, asparagus, lettuce, broccoli, Brussels sprouts, cauliflower, green beans, kale, and mushrooms. Fats are obtained from natural sources such as butter, olive oil, nuts, and seeds. High-starch veggies are avoided (beets, peas, corn, potatoes, sweet potatoes, yams) as are all forms of processed carbs, sugar, and starch.
Eating carbs stimulates the production of insulin. This leads to fat production and retention and a reduced ability to burn fat.
When a person greatly reduces their carbohydrate intake and consumes more calories from fat, their body begins to burn stored fat as a source of energy—instead of using carbohydrates as its main fuel source.
Eventually this results in weight loss. Certain studies indicate that weight reduction also occurs because the additional protein and fat being consumed keep a person feeling fuller longer, so overeating is less common.
Beyond weight loss, low-carb diets are heralded for improving health conditions such as metabolic syndrome, diabetes, cardiovascular disease, and high blood pressure.
Through a reduced intake of carbs, the body’s insulin levels are lowered. In an online survey of an international social media group for those with Type 1 diabetes, it was found that children and adults who followed a very low-carbohydrate diet had exceptional glycemic control of their diabetes without high rates of acute complications. If confirmed by clinical trials, the results suggest that chronic complications of this disease might be prevented through diet.
Those with cardiovascular risk may also benefit from low-carb eating plans. High-density lipoprotein (HDL) cholesterol and triglyceride levels may improve slightly with low-carb diets versus moderate-carb diets. Large randomized controlled trials, which monitored individuals for at least six months, showed that restricting carbs improved lipid markers better than when low-fat diets were followed.
Any diet can cause changes within the body, including low-carb plans. Some people find that constipation is common when reducing carbohydrates. Since most people get their dietary fiber from breads, pastas, and starchy vegetables, when these foods are reduced or eliminated, a person’s fiber intake can drop drastically and constipation results.
A sudden and drastic cut of carbs may also cause bad breath, muscle cramps, skin rash, fatigue, and headaches. Some low-carb diets restrict carbohydrates in such great amounts that nutrient deficiencies, gastrointestinal difficulties, and bone loss may occur in the long term.
Low-carb eating plans are not recommended for children, preteens, and teens as their developing bodies need the nutrition found in a variety of fruits, vegetables, and whole grains.