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.
What time period works best? Keeping your eating window earlier—say, from 7 a.m. to 3 p.m.—seems to be the most beneficial. The body’s biological clock is primed to eat earlier in the day, explains Courtney Peterson, PhD, assistant professor of nutrition at the University of Alabama at Birmingham. “In most people, blood sugar control is best in the morning and gets worse as the day progresses. You also digest food faster in the morning. So there’s a metabolic advantage to eating earlier in the daytime,” she says.
Just remember: While you don’t have to track your calories during your eating window, you shouldn’t let things turn into a free for all. “It’s smarter to still eat moderately,” Peterson says. Stick with mostly healthy, minimally processed foods like lean proteins, complex carbs, and plenty of fruits and vegetables. As for portions? Eat until you’re satisfied, not stuffed.
Second, fasting seems foreign to many of us simply because nobody talks about it that much. The reason for this is that nobody stands to make much money by telling you to not eat their products, not take their supplements, or not buy their goods. In other words, fasting isn't a very marketable topic and so you're not exposed to advertising and marketing on it very often. The result is that it seems somewhat extreme or strange, even though its really not.
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.
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.
Jerimiah, the linked study in the article (https://www.sciencedirect.com/science/article/pii/S1550413118302535) specifically studied “eTRF”(Early Time-Restricted Feeding) from 8am – 2pm, and implies that eating earlier is better than later. I haven’t read the study (it’s behind a damn Elsevier pay-wall), so I don’t know how strongly they feel about early vs late, though. For me, personally, 12-8 is doable, and skipping dinner (given the existence of a family and the desire to have dinner with said family) isn’t doable, so I’m pleased to hear from you and April above that it’s working. Just starting!
I’ll share some of my experiences, now doing heavy strength training for 3 years in a fasted state: For my first “fasted” workout or two after starting an IF protocol, it was very weird to not eat before training. However, after a few sessions, I learned that my body could certainly function (and even thrive) during my training sessions despite not eating a pre-workout meal.
I decided to follow time-restricted eating, or fasting 18 hours out of the day and eating the other six (no food between 8pm and 2pm). The first day I managed to abstain all 18 hours, but it wasn't pretty (here's what happens to your body when you skip a meal). My mind was racking up obsessive food thoughts faster than my phone hunts Pokemon. The inner dialogue went something like this: I'm hungry, I'm hungry, I'm friggin hungry, I'm hungry, I'm STARVING, get this girl a cookie already!
Forms of intermittent fasting exist in religious practices in various groups across the world. Religious fasting regimens include, but are not limited to, Vrata in Hinduism, Ramadan fasting (Islam), Yom Kippur fasting (Judaism), Orthodox Christian fasting, Fast Sunday (The Church of Jesus Christ of Latter-day Saints), and Buddhist fasting. Certain religious fasting practices, only require abstinence from certain foods, while others, like the Jewish fast on Yom Kippur, last for a short period of time and would cause negligible effects on the body.
Live It! This phase is a lifelong approach to diet and health. In this phase, you learn more about food choices, portion sizes, menu planning, physical activity, exercise and sticking to healthy habits. You may continue to see a steady weight loss of 1 to 2 pounds (0.5 to 1 kilogram) a week until you reach your goal weight. This phase can also help you maintain your goal weight permanently.