Losing weight comes down to consuming fewer calories than your body requires for energy. Extra calories, extra weight. Simple. Not quite, there are of course so many factors that mean staying within the correct calorie parameters is not always possible—your desk-bound job, that extra glass of red wine or that really gooey chocolate pudding you couldn’t resist (and why should you?). But if you only cheat sometimes and pretty much eat a healthy, balanced, diet and you’re still not losing weight? Then the answer could be down to timing. Or intermittent fasting, to be precise. Keep scrolling to find out what we mean and why this intermittent fasting guide could be the answer to dropping those stubborn extra pounds of fat…
Intermittent fasting (IF) is an umbrella term for lots of different diets, but essentially it is where you fast for a set period of time triggering fat loss. There are numerous methods out there but three of the most popular are:
Alternate-day fasting (ADF) where you fast every other day. Krista Vardy’s The Every Other Day Diet (£13) is a good source for this IF protocol.
Lean Gains encourages daily fasting. It was devised by Martin Berkhan, a PT and nutritional advisor, for people who weight-train and want to lose fat but not muscle. Women fast for 14 hours and men 16 hours, then feed for the remaining 10 or eight hours.
The Fast Diet (£6), created by journalists Michael Mosley and Mimi Spencer, involves eating normally for five days each week and restricting your calories on two non-consecutive days (you have the freedom to choose the days)—otherwise known as the 5:2 diet.
On the 5:2 plan, you can expect to lose a pound per week; if not its co-author recommends switching to a 4:3 split. On the ADF you should see two pounds lost.
The Lean Gains protocol is trickier to gauge. Because the aim is to lose fat and gain muscle (which weighs more than fat), you may not see such a drastic weight loss on the scales, despite fasting for a window of time every day.
There are numerous health benefits of fasting over and above just fat loss. A 2014 review led by Professor Valter Longo, a leading researcher into human longevity, found that fasting reduced oxidative damage and inflammation, optimised energy metabolism and bolstered cellular protection. It also helps reduce obesity, hypertension, asthma and rheumatoid arthritis. Impressive.
But it wasn’t just internal improvements; fasting could be a welcome addition to your daily skincare routine too. Hear us out. In the review, fasting was linked with a slowing down of the ageing process. Inflammation and oxidative damage were reduced during the fasting period. In the review Longo wrote, “Fasting for 3 or more days causes a 30% or more decrease in circulating insulin and glucose, as well as rapid decline in the levels of insulin-like growth factor 1 (IGF-1), the major growth factor in mammals, which together with insulin is associated with accelerated aging and cancer (Fontana et al., 2010).”
On top of all that, scientists are now discovering that fasting could be linked with healthier gut microbiota, which we know can lead to better skin and mood. Nutritionist Sarah Macklin explains, “Constant grazing has been found to upset our microbes—whereas a 12+ hour fast allows our microbes to rest and interact with our gut lining to boost our metabolism. Therefore, skipping breakfast may be a good thing.”
Research into fasting is still in its infancy, “The American Journal of Clinical Nutrition found for women, alternate-day fasting could actually lower glucose tolerance and potentially crash your metabolism. Another concern is ADF may contribute to eating disorders or an unhealthy obsession with food,” warns Macklin.
Also, the ADF and 5:2 diets can be tricky to stick to if you have a busy lifestyle or socialise a lot. “The most manageable way of IF would be to do most of it through sleeping hours, however I wouldn’t recommend active, stressed or disordered women to try IF,” adds Macklin. With the Lean Gains method, as a woman you can fast from 10 p.m.–12 noon, this still allows you to go out for lunch or dinner.
The key with fasting is compliancy, you need to stick to a fast long-term to reap the health benefits that go above and beyond just fat loss.
Water is allowed! And after that, it depends on which method you follow. For instance, if you’re following Berkhan’s Lean Gains protocol, you shouldn’t consume any calories, although he states, “coffee, calorie-free sweeteners, diet soda and sugar-free gum are okay.”
On the Every Other Day Diet and the 5:2 Fast Diet, you can consume 500 calories on fast days. Vardy recommends healthy foods, but when they carried out a study, it found that those who consumed 500 calories of fatty foods lost just as much weight as those who ate healthier. On the Fast Diet website, Michael Mosley says, “The basic principle is to eat foods that are high in protein and fibre, as these are the most satiating. That means fish, meat, vegetables.”
Krista Vardy, author of The Every Other Day Diet, told huffingtonpost.co.uk, “You can exercise. We analysed a group of dieters at our research centre, who exercised 3 times a week. We also let people choose whether to exercise on feast or fast days, and they chose equally.
“During the first week participants reported low energy, but it bounces back. Some people even report more energy on fast days.
“It’s actually advisable to exercise because you lose more weight if you do so - your muscle mass will stay high and, as a result, so will your metabolism.”
Don't fancy fasting? Check out the Sirtfood Diet instead…