Low-carb diets may 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 shed excess weight can reduce or even reverse risk factors for cardiovascular disease and diabetes. Most weight-loss diets — not just low-carb diets — may improve blood cholesterol or blood sugar levels, at least temporarily.
Many people on a ketogenic diet report sleeping much deeper, says Pamela Ellgen, a personal trainer and author of Sheet Pan Ketogenic. However, during the adjustment period (the first three to five days after you start keto), you may experience insomnia or difficulty staying asleep. This will end once your body adjusts to ketosis and burning stored fat. Then, you may find you're able to sleep longer, sleep deeper, and feel more relaxed and rested when you wake up. Here are 15 things you need to know before starting the keto diet.

In the first few days of the keto diet, it's not uncommon for people to experience the "keto flu," a brief period in which you may have headaches, fatigue, confusion, and nausea. These symptoms are a sign that your body is making the switch from burning glucose (sugar from carbs) for energy to burning fat—a process called ketosis. The changeover can leave you feeling depleted for a day or two, but once you break through to the fat-burning phase, you may find you have much more energy and greater endurance. "You are able to do more without hitting 'the wall,' says Carrie Burrows, PhD, a health and fitness expert. "When we use fat as fuel, our endurance improves and is more sustainable." That extra energy will carry over to your workouts, Dr. Burrows says. Here are more things you need to know before starting the keto diet.


Low-carb diets may improve high-density lipoprotein (HDL) cholesterol and triglyceride values slightly more than do moderate-carb diets. That may be due not only to how many carbs you eat but also to the quality of your other food choices. Lean protein (fish, poultry, legumes), healthy fats (monounsaturated and polyunsaturated) and unprocessed carbs — such as whole grains, legumes, vegetables, fruits and low-fat dairy products — are generally healthier choices.
Controlling your blood sugar levels helps you control your cravings, Dr. Burrows says. "When we are not on a sugar roller coaster from processed carbohydrates, most people make better food choices because they are not looking for their next hit of food," she says. You may also find you're able to go longer periods without eating, he says. Intermittent fasting is a common practice among dieters who've been eating keto for a while. Learn how one woman totally kicked her sugar habit by trying the keto diet.
In addition to helping you lose weight, ketosis may also increase your energy, improve your concentration, decrease inflammation and improve your blood sugar markers, reducing your risk of developing diabetes. A study published in the journal Seizure in 2014 also linked ketosis to reduced severity and frequency of seizures in those with epilepsy and a slower progression of Alzheimer's disease.
Although it’s true that your brain has high energy demands and requires some glucose, when you’re in ketosis, there are plenty of ketones to supply a good portion of its fuel. Fortunately, your liver will always make the small amount of glucose your brain needs, even under conditions of complete starvation. This process, known as gluconeogenesis (literally “making new glucose”), can also provide glucose for other structures that need it, such as the red blood cells and a portion of the kidneys.
Use our premium meal planner tool (free trial) to access tons of weekly meal plans, complete with shopping lists. You can adapt the diet plans to your liking, skipping any meal, choosing how many people you’re cooking for, and the shopping lists adapt. You can even start a new plan from scratch (of from pre-existing ones), tailor them completely and save them.
People claiming huge benefits of these supplements – despite the lack of solid scientific support – may sometimes have a financial reason to believe in the supplements. Some of these products are sold under a multi-level marketing arrangement, where sales people are paid based on commission. For example, the company Prüvit sells drinkable ketones, called KETO//OS, with a multi-level marketing structure.
Low-carb diets may improve high-density lipoprotein (HDL) cholesterol and triglyceride values slightly more than do moderate-carb diets. That may be due not only to how many carbs you eat but also to the quality of your other food choices. Lean protein (fish, poultry, legumes), healthy fats (monounsaturated and polyunsaturated) and unprocessed carbs — such as whole grains, legumes, vegetables, fruits and low-fat dairy products — are generally healthier choices.
In addition to helping you lose weight, ketosis may also increase your energy, improve your concentration, decrease inflammation and improve your blood sugar markers, reducing your risk of developing diabetes. A study published in the journal Seizure in 2014 also linked ketosis to reduced severity and frequency of seizures in those with epilepsy and a slower progression of Alzheimer's disease.

While these findings are preliminary, in one study of mice, the keto diet helped reduce anxiety. The research suggests this could be due to the protective brain benefits of intake of healthy fats and low levels of sugar. A follow-up study found that mice exposed to a ketogenic diet while in utero showed less susceptibility to anxiety and depression than mice born to mothers who were not on the keto diet. Here's what it's really like to follow the keto diet.
Another benefit of ketosis is an unlimited supply of energy for your body. Your body can only store a certain amount of carbohydrates in your liver and your muscles, but there's no limit to the amount of fat it can store. According to a report published in Nutrition Reviews in 2018, your body can store a total of 600 grams of glycogen, which is divided between the liver and your muscles. On the other hand, it can store as much fat as you give it.

The studies done on ketosis and endurance sports performance paint a pretty clear picture – it helps.  One of the most detailed studies on fat utilisation and performance (compared to a standard carb diet) was named the FASTER study - the results found that those who were on a ketogenic type diet had more mitochondria than the control group, lower oxidative stress, lower lactate load and that the fat adapted and fuelled athletes could function off fat for a much higher intensity than the non-fat adapted counter parts.
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