Low-carbohydrate diets or low carb diets, are food diet programs for weight loss and dietary health that advocate restricted carbohydrate consumption, based on research that ties carbohydrate consumption with increased blood insulin levels, and increased insulin with obesity.
Under these various dietary programs, foods containing carbohydrates (like sugar, grains, and starches) are limited or replaced in favor of foods containing more protein and fat. Vegetables, though classified as carbohydrates, are thought to be far healthier than grain-based carbohydrates. Programs such as the South Beach, Atkins and Zone diets, are claimed to “work” because they reduce insulin levels, which in turn causes the body to burn its fat for energy.
As a process, these kinds of diets have been in and out of fashion since the Banting diet appeared in the 19th century. But long before modern scientific invention, anecdotal and holistic prescriptions, containing passages about limiting certain foods, including foods of mostly carbohydrates, have appeared throughout history. Although strong evidence suggests, and general agreement claims, that low carb diets can help achieve weight loss, some have been controversial among nutritionists, and their relative safety has been challenged.
In 2004, a Canadian court ruled that foods sold in Canada could not be marketed with reduced or eliminated carbohydrate content as a selling point because carbohydrates were determined not to be a health risk, and that existing “low carb” and “no carb” packaging would have to be phased out by 2006.