Someone on a high-carbohydrate diet may never go beyond the catabolic state as they always have a reserve of glycogen. However, someone on a low-carb diet and exercising regularly can get through very quickly (the “Keto diet”, in which you cut out almost all carbohydrates in order to keep blood sugar levels and glycogen stores low, works the same). “I’d move off intermittent fasting for fat loss, and if you choose to adopt it, think about the health benefits,” says Clarkson.
How to Fast
“To fast, you have to downregulate your hunger,” says Clarkson. Hunger is felt when ghrelin, a hormone released by our stomach, triggers the production of two other hormones called NPY and AgRP in the hypothalamus.
While these three hormones make you feel hungry, there are a variety of others that suppress it. Sometimes referred to as “satiety hormones”, it is one of the most important hormones Leptin, released from fat cells to suppress the production of ghrelin – Basically, you are telling the body “here is fat to burn”.
Ghrelin is sometimes referred to as the short-term hunger reaction because it is released when the stomach is empty and there is less pressure on the stomach wall. It can be overridden to a certain extent by drinking water. Leptin now has a long-term effect.
“Our hunger hormones are regulated by many things, including genetics,” says Clarkson. “But when you think about the nerves connected to our stomach and digestive tract – if your stomach isn’t bloated, your body will think it’s hungry.” She adds that hydration can help with those early feelings of hunger until your body adapts. “The first few weeks will be tough, but you get used to it.”
For most people, ketosis occurs 12-24 hours after a meal. So if you have dinner between 6:00 p.m. and 8:30 p.m., nutritional status ends between 9:00 p.m. and 11:30 p.m., and ketosis and autophagy can occur at 6:00 a.m. to 8:30 a.m. the next morning. “But most people sit down and open a box of something else after dinner,” says Clarkson. “Snacks or sugary drinks and beer extend food intake by three hours. If you finish snacking at 9:30 pm-10:00pm, the full state will move to 1:00 am-3:00am, ”she says. This could mean the ketosis never occurs until the next time you have a meal.
“If you can make the informed decision to have dinner an hour early and not snack, you may end up in this state of ketosis in the morning as opposed to someone who has the high carb dinner and snacks and at 6am wakes up: 00 and never got into this state, ”she says. Clarkson suggests eating early on a Sunday evening or having breakfast an hour later and building up from there a day or two a week.
If done carefully, intermittent fasting can help your body make its own repairs and recoveries. Autophagy appears to decrease with age, so it can be useful to strengthen yourself later in life. Be aware, however, that this may not be the right weight loss strategy and nothing can replace a balanced diet.
William Park is the Senior Journalist at BBC Future and is @williamhpark on twitter.
All of the content in this article is presented for general information only and should not be viewed as a substitute for medical advice from a healthcare professional. You should speak to your health care professional if you are pregnant or have a condition such as diabetes and are considering intermittent fasting, plan to fast long-term, and you should not avoid fluids while fasting.
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