A low carbohydrate diet limits carbohydrates from grains, starchy vegetables, fruits, and emphasizes foods high in protein and fat. It is used for weight loss, health benefits, and reducing disease risks. While it can help with weight loss, there are risks like headaches, weakness, and fatigue. Long term, it may increase the risk of gastrointestinal issues, chronic diseases, and vitamin/mineral deficiencies. Ketosis occurs when the body breaks down stored fat for energy due to a lack of carbohydrates, producing ketones. However, the American Heart Association says there is not enough evidence that low carb diets provide heart healthy benefits.