Keto blogs and weight-loss websites recommend taking precautions—like making sure you’re staying hydrated, getting plenty of sleep, and finding ways to manage stress—to reduce the unpleasant effects of the ketogenic diet on your body. Some also recommend electrolytes, ketone supplements, or bone broth (which is high in sodium and other minerals) to replace some of what the body is missing in the early stage of the diet.
Normal dietary fat contains mostly long-chain triglycerides (LCTs). Medium-chain triglycerides (MCTs) are more ketogenic than LCTs because they generate more ketones per unit of energy when metabolised. Their use allows for a diet with a lower proportion of fat and a greater proportion of protein and carbohydrate, leading to more food choices and larger portion sizes. The original MCT diet developed by Peter Huttenlocher in the 1970s derived 60% of its calories from MCT oil. Consuming that quantity of MCT oil caused abdominal cramps, diarrhea, and vomiting in some children. A figure of 45% is regarded as a balance between achieving good ketosis and minimising gastrointestinal complaints. The classical and modified MCT ketogenic diets are equally effective and differences in tolerability are not statistically significant. The MCT diet is less popular in the United States; MCT oil is more expensive than other dietary fats and is not covered by insurance companies.
In general, a low-carb diet focuses on proteins, including meat, poultry, fish and eggs, and some nonstarchy vegetables. A low-carb diet generally excludes or limits most grains, legumes, fruits, breads, sweets, pastas and starchy vegetables, and sometimes nuts and seeds. Some low-carb diet plans allow small amounts of certain fruits, vegetables and whole grains.
"Your body will often shift metabolism when you do something different to it -- but it equalizes -- you see a rapid shift and a return to normal -- and the longer-term studies show normal results in this area," says Sondike. Still, he tells WebMD it's a "smart idea" to take a calcium supplement beginning at the start of your low-carb diet to safeguard against a possible deficiency. Tofu can also be a good source of calcium.
But beyond that, experts aren't convinced that the keto diet has any other scientifically proven health benefits. In fact, it may have some distinct downsides. If you follow the keto diet incorrectly, for example (like by eating lots of saturated fats, versus healthy unsaturated fats), you're at risk of raising your cholesterol levels. “The best strategy to keep your heart healthy is to get as much fat as possible from unsaturated sources such as olive, avocado and canola oils, nuts, seeds, avocados, and olives," says Ansel. For some people, it's possible to actually improve cholesterol if the fats in their diet are from varied and healthy sources, says Harvey.
Remember, your water and electrolyte intake needs to go up on a keto diet, and dehydration can exacerbate many keto flu symptoms. There’s no hard and fast recommendation for how much water keto dieters should be drinking, Nico says. But in general, you should be sipping enough so that your urine stays clear or pale yellow. As for electrolytes like sodium? A registered dietitian can help you figure out how much more you should be having and the best places to get it. If you're feeling sick and can't see a nutritionist right away, consider mixing a low-carb electrolyte drink into your water.
If you have diabetes, it’s important to understand the difference between nutritional ketosis and ketoacidosis. Both involve ketones. But ketoacidosis is a dangerous condition that happens when your body doesn’t have enough insulin and ketones build up too much. Symptoms include excessive thirst, urinating often, confusion, and weakness or fatigue. It’s more common for people with type 1 than type 2.
It seems strange that a diet that calls for more fat can raise “good” cholesterol and lower “bad” cholesterol, but ketogenic diets are linked to just that. It may be because the lower levels of insulin that result from these diets can stop your body from making more cholesterol. That means you’re less likely to have high blood pressure, hardened arteries, heart failure, and other heart conditions. It's unclear, however; how long these effects last.
People use a ketogenic diet most often to lose weight, but it can help manage certain medical conditions, like epilepsy, too. It also may help people with heart disease, certain brain diseases, and even acne, but there needs to be more research in those areas. Talk with your doctor first to find out if it’s safe for you to try a ketogenic diet, especially if you have type 1 diabetes.