Touted as the latest waist-cinching miracle, Intermittent Fasting has a devoted following of dieters, bodybuilders and even doctors, but is it really the answer to our weight loss prayers?
Unlike regular diets, Intermittent Fasting (IF) doesn’t restrict what you eat, but rather when you eat, with fasting periods lasting between 16 and 24 hours. If you think about it, it’s not really such a novel idea. Go back a few thousand years and you’ll see a whole lot of humans (sometimes unwillingly) practicing Intermittent Fasting. No luck catching a gazelle this morning? Better luck tomorrow. In the meantime, here’s a handful of wild berries to tide you over! If you want a more contemporary example of fasting, think about the foodless eight-hour stretches you experience every night, and the aptly named meal you have in the morning.
Intermittent Fasting is not synonymous with starvation. With most Intermittent Fasting practices, the basic breakdown is this: there are “feast” days, when you eat as you normally would, and there are “fast” days where, depending on the particular regimen, you either consume about 500 calories or none at all. At most, you restrict you food intake for 24 hours, which is not enough time to send your body a distress call, slowing down your metabolism and body’s non-essential functions. Some studies suggest that Intermittent Fasting might actually rev up your metabolism and encourage greater fat burn.
The popularity of Intermittent Fasting as a weight loss tool is due partly to the fact that people find it easier to stick with than the alternative calorie-restriction diets. Since your food choices aren’t restricted, you don’t have to give up the foods you love. Traditional diets ask you to both monitor the quality of the calories you eat as well as the quantity, day in and day out. You’re asked to say no to pizza, no to cake, no to all the terrible things you love. With Intermittent Fasting, you only have to say no to them today, comforted by the knowledge that tomorrow you can roll up your cake in a pizza slice and call it a burrito.
So, then, how do you lose weight if you can just make up for lost time the following day? That’s an excellent question. Dr. Krista Varady is elbow-deep in Intermittent Fasting research. So deep, in fact, that she published a book about it called The Every-Other-Day Diet: The Diet That Lets You Eat All You Want (Half the Time) and Keep the Weight Off. She has been studying the effect of IF on weight loss for years, and her research has consistently found that alternating feast and fast days aids weight loss and decreases the risk for coronary artery disease.
During one study, participants ate 25% of their regular calories on fast days. You would think that eating only 25% of your normal calories on Monday, would mean eating 175% on Tuesday to make up the difference. But, as Dr. Varady’s study found, participants ate only 15% above their usual intake on their feast days. Let’s say you’re alternating fast and feast days and your normal calorie intake is 2000. If we assume you’ll eat 500 calories on your fast days and 2,300 on your feast days, that means by the end of the week you’ll save between 5100 and 5600 calories.
Still, you should be wary of binge eating. Too often, people restrict their calorie intake drastically, only to break days (or sometimes just hours) later and eat candy like they’re an unhinged eight-year old on Halloween. Though Intermittent Fasting does not limit what you eat, it’s important to not overcompensate on your eating days; otherwise, your efforts will be futile.
Three popular fasting methods:
8/16 Rule
This may be the easiest of the fasting programs to follow. Limit your food intake to an 8-hour period of the day; fast for the other 16 hours. If you factor in sleep, it becomes very manageable. For example, you could limit your meals to between 10 AM and 6 PM.
One Day On, One Day Off
Simple to remember: eat normally on Day 1, fast on Day 2. Repeat. You should allow yourself 25% of your usual calories on Day 2, preferably eaten as one meal. If you’re a gym goer, try to time your fast days with your days off from the gym or stick to low-impact exercises and stretches.
The 5:2 Diet
Each week, pick two non-consecutive fast days and consume between 500 and 600 calories on those days. Eat normally the rest of the week.
Additional Benefits
The research regarding Intermittent Fasting’s positive effects on health factors other than weight has been limited, and with only a recent surge in popularity the long-term effects of IF aren’t known. Most experiments on the effects of fasting have been done on rats. And, though the results have been overwhelmingly positive, a stroke-resistant, age-defying rat population may not be such a good thing.
The most promising human research suggests that Intermittent Fasting could make you live longer. The most conclusive (albeit dated) human evidence comes from a Spanish study conducted in the 1950s. Researchers divided a group of 120 elderly men and women into two groups of 60. The first group fasted on alternate days; the other ate regularly. At the end of three years, six of the fasters had died, while the non-fasting group had lost 13 participants. The fasting group also recorded fewer visits to the infirmary, at 123, as opposed to the non-fasting group’s 219 visits. There is also some evidence that IF causes an increased responsiveness to insulin and lowers the risk of diabetes, as well as blood sugar and cholesterol levels.
Some healthcare professionals and regular people remain skeptical about the benefits of IF. As we know, weight isn’t always an indicator of health and though IF will help you shed pounds, it does not guarantee the prevention of muscle loss, nutrient deficiency or hormonal changes. Most importantly, IF does not on its own encourage long-term, healthy habits, which are vital if you want to stay in shape. But, if you’ve been struggling with your weight and have tried everything to no avail, then Intermittent Fasting may indeed be the answer you’ve been looking for.
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