I am a 65-year-old male who started IF seven weeks ago. I only eat between noon and 8pm. I am obese, but losing about a pound a week so far. Notably, except for time, I have not changed what I eat at all. My diet was never terrible or great, and now it is the same, a mix of raw fruit sometimes and a donut another time. But I only eat it during the appointed hours. Remarkably, I do not feel hungry. I used to eat comfort breakfasts like pancakes or waffles, and I thought I would miss them. But no, I truly am not hungry in the mornings. I often delay lunch, but I still stop eating at 8. That alone probably has cut many calories of desserts. Bottom line: works for me so far.
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.
Over 8–10 mmol/l: It’s normally impossible to get to this level just by eating a keto diet. It means that something is wrong. The most common cause by far is type 1 diabetes, with severe lack of insulin. Symptoms include feeling very sick with nausea, vomiting, abdominal pain and confusion. The possible end result, ketoacidosis, may be fatal and requires immediate medical care. Learn more
On a ketogenic diet, your entire body switches its fuel supply to run mostly on fat, burning fat 24-7. When insulin levels become very low, fat burning can increase dramatically. It becomes easier to access your fat stores to burn them off. This is great if you’re trying to lose weight, but there are also other less obvious benefits, such as less hunger and a steady supply of energy. This may help keep you alert and focused.
There are three instances where there’s research to back up a ketogenic diet, including to help control type 2 diabetes, as part of epilepsy treatment, or for weight loss, says Mattinson. “In terms of diabetes, there is some promising research showing that the ketogenic diet may improve glycemic control. It may cause a reduction in A1C — a key test for diabetes that measures a person’s average blood sugar control over two to three months — something that may help you reduce medication use,” she says.

When you eat less than 50 grams of carbs a day, your body eventually runs out of fuel (blood sugar) it can use quickly. This typically takes 3 to 4 days. Then you’ll start to break down protein and fat for energy, which can make you lose weight. This is called ketosis. It's important to note that the ketogenic diet is a short term diet that's focussed on weight loss rather than the pursuit of health benefits. 
Even though this plan is advanced, it's very simple. Don't eat anything every other day. This is the most intense form of fasting but can produce amazing results. Every other day, eat healthy fats, clean meat sources, vegetables, and some fruit, and then on your fasting days, you can consume water, herbal tea, and moderate amounts of black coffee or tea.

On a ketogenic diet, you’re generally eating a diet that’s high in fat (roughly 70 percent of your total calories come from fat), moderate in protein (about 20 percent of your calories), and low in carbohydrate (about 5 percent of calories). By limiting carbohydrates (to usually less than 45 grams for the average person), your body lacks the glucose (from carbs) that it normally uses for energy, so it eventually switches over to burning fat as its primary fuel source instead; through a metabolic process called ketosis, the liver converts the fat into fragments of fatty acids called ketones, which power the brain and other organs and tissues.
I am a 65-year-old male who started IF seven weeks ago. I only eat between noon and 8pm. I am obese, but losing about a pound a week so far. Notably, except for time, I have not changed what I eat at all. My diet was never terrible or great, and now it is the same, a mix of raw fruit sometimes and a donut another time. But I only eat it during the appointed hours. Remarkably, I do not feel hungry. I used to eat comfort breakfasts like pancakes or waffles, and I thought I would miss them. But no, I truly am not hungry in the mornings. I often delay lunch, but I still stop eating at 8. That alone probably has cut many calories of desserts. Bottom line: works for me so far.

Implementing the diet can present difficulties for caregivers and the patient due to the time commitment involved in measuring and planning meals. Since any unplanned eating can potentially break the nutritional balance required, some people find the discipline needed to maintain the diet challenging and unpleasant. Some people terminate the diet or switch to a less demanding diet, like the modified Atkins diet or the low-glycaemic index treatment diet, because they find the difficulties too great.[42]
The first modern study of fasting as a treatment for epilepsy was in France in 1911.[12] Twenty epilepsy patients of all ages were "detoxified" by consuming a low-calorie vegetarian diet, combined with periods of fasting and purging. Two benefited enormously, but most failed to maintain compliance with the imposed restrictions. The diet improved the patients' mental capabilities, in contrast to their medication, potassium bromide, which dulled the mind.[13]
When you eat foods high in carbohydrates and fat, your body naturally produces glucose. Carbohydrates are the easiest thing for the body to process, and therefore it will use them first – resulting in the excess fats to be stored immediately. In turn, this causes weight gain and health problems that are associated with high fat, high carbohydrate diets (NOT keto).
Understanding the potential adverse effects of intermittent fasting is limited by an inadequate number of rigorous clinical trials. One 2015 review of preliminary clinical studies found that short-term intermittent fasting may produce minor adverse effects, such as continuous feelings of weakness and hunger, headaches, fainting, or dehydration.[33] Long-term, periodic fasting may cause eating disorders or malnutrition, with increased susceptibility to infectious diseases.[33]

The benefits above are the most common ones. But there are others that are potentially even more surprising and – at least for some people – life changing. Did you know that a keto diet can help treat high blood pressure, may result in less acne, may help control migraine, might help with certain mental health issues and could have a few other potential benefits?
I would like to know what led you to the conclusion to recommend eating in the morning and fasting in the evening instead of the other way around. You do not link any studies here that show TRF in the morning is better than TRF in the evening. You do state “Nighttime eating is well associated with a higher risk of obesity, as well as diabetes.” but I would hazard a guess that alot people that snack into the evening have many other factors at play that could effect their risk of obesity and diabetes and are possibly not fasting at all. I have been doing TRF from 12-8pm every day for almost a year and have seen vast improvements in my health, not least of which is a loss of 70 lbs, so it seems odd to read items 3 and 4 on your 4 ways to use this information for better health. If you have evidence that supports the idea that TRF in the evening is bad then I would like to see it and perhaps change my dieting habbits.
Hello Myriam, I am a dual certified personal trainer and Sports Nutrition Specialist. I really love how concisely you have put this article together. I did notice that on your macro breakdown for a 1500 calorie diet you actually listed the protein intake at around 31% of the daily calories (117*4=468..468/1500=.31). I was wondering if you did this to bring the protein amount closer to 1 gram per pound of body-weight to preserve lean mass?
In the 1960s, medium-chain triglycerides (MCTs) were found to produce more ketone bodies per unit of energy than normal dietary fats (which are mostly long-chain triglycerides).[15] MCTs are more efficiently absorbed and are rapidly transported to the liver via the hepatic portal system rather than the lymphatic system.[16] The severe carbohydrate restrictions of the classic ketogenic diet made it difficult for parents to produce palatable meals that their children would tolerate. In 1971, Peter Huttenlocher devised a ketogenic diet where about 60% of the calories came from the MCT oil, and this allowed more protein and up to three times as much carbohydrate as the classic ketogenic diet. The oil was mixed with at least twice its volume of skimmed milk, chilled, and sipped during the meal or incorporated into food. He tested it on 12 children and adolescents with intractable seizures. Most children improved in both seizure control and alertness, results that were similar to the classic ketogenic diet. Gastrointestinal upset was a problem, which led one patient to abandon the diet, but meals were easier to prepare and better accepted by the children.[15] The MCT diet replaced the classic ketogenic diet in many hospitals, though some devised diets that were a combination of the two.[10]
Be choosy about carbs. You can decide which ones you eat, and how much. Look for those that are low on the glycemic index (for instance, asparagus is lower on the glycemic index than a potato) or lower in carbs per serving than others. Whole grains are better choices than processed items, because processing removes key nutrients such as fiber, iron, and B vitamins. They may be added back, such as in “enriched” bread.
It usually takes three to four days for your body to go into ketosis because you have to use up your body's stores of glucose, i.e., sugar first, Keatley says. Any major diet change can give you some, uh, issues, and Keatley says he often sees patients who complain of IBS-like symptoms and feeling wiped out at the beginning of the diet. (The tiredness happens because you have less access to carbs, which give you quick energy, he explains.)
There are many reasons why you might want to lose weight. If you have been significantly overweight or obese for a long time, then you might have concerns about what the extra weight could be doing to your health. Obesity increases your risk of many health problems, including diabetes, non-alcoholic fatty liver disease, gallbladder disease, and some types of cancer.[1] If you have recently gained a bit of weight, then you might just want to lose some weight to fit back into your old jeans. Whatever your reason for wanting to lose weight, there are some important strategies that you should know about.
In addition, the healthy habits and kinds of foods recommended on the Mayo Clinic Diet — including lots of vegetables, fruits, whole grains, nuts, beans, fish and healthy fats — can further reduce your risk of certain health conditions. The Mayo Clinic Diet is meant to be positive, practical, sustainable and enjoyable, so you can enjoy a happier, healthier life over the long term.
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