The Skinny on Intermittent Fasting The British Invasion is happening all over again, except this time, we’re importing the latest weight loss craze instead of infectious rock music. The hottest diet trend in the UK – intermittent fasting – is now taking off in the US. While these fasting diets come in range of shapes and sizes, all of them are variations on the same basic theme: on select days of the week, you heavily restrict your calories to help you shed pounds. The rest of the time, you eat a typical calorie load (in many cases, you decide what’s “typical”). Because you’re only restricting your food intake a few days a week instead of 24/7, proponents say you feel less deprived and are more likely to stick with the diet long enough to see results…but there are some downsides to consider, too. The bestselling book The FastDiet kicked off the fasting frenzy in England earlier this year. This plan advocates what is referred to as “5:2 intermittent fasting” – two days a week, dieters limit themselves to 500 calories (or 600 if they’re male), and the remaining five days, they eat normally. The book’s author, UK medical television journalist Dr. Michael Mosley, claims that fasting can help you shed pounds quickly, and also improve your blood pressure, cholesterol, and insulin sensitivity. Another popular plan, the 2-Day Diet, takes a slightly different approach. This book, which made its US debut just a few weeks ago, instructs dieters to eat a low-carbohydrate, low-cal menu (around 1,000 calories for females and 1,100 for males) on two restricted days each week and a heart-healthy, Mediterranean-style diet on five unrestricted days. The Science of Fasting Dr. Michelle Harvie, author of the 2-Day Diet, based the plan on intermittent fasting studies she conducted as a research dietitian at the Genesis Breast Cancer Prevention Center in England. In one study, published in 2011, Harvie and her colleagues assigned 107 overweight and obese women to one of two weight loss plans. Half of the participants followed a traditional, or “continuous diet” – every day, they ate 25 percent fewer calories than their daily calorie requirement. The second group also reduced their total weekly calories by 25 percent, but instead of spreading the deficit out over seven days, they cut their calories more severely for just two days a week (the women ate about 650 calories on the two fasting days). Both groups lost the same amount of weight – around 13 pounds in 6 months, on average – and saw similar improvements in cholesterol levels, blood pressure, and other health indicators. Supporters cite this research as evidence that intermittent fasting is an effective way to shed excess pounds. But viewed from another angle, the study shows that fasting doesn’t offer a significant advantage over the classic dieting approach. It’s no surprise that the women dropped the same number of pounds, regardless of which plan they followed. “Calories in versus calories out” is the most important determinant of weight loss, and if you cut the same number of calories over the course of a week, when you cut those calories shouldn’t make a difference. Either method can work as long as you stick with it. However, that’s precisely where the fasting method can get tricky. The basic premise of these trendy new diets is that it’s easier to diet two days a week than seven, and in Harvie’s 2011 study, those following the intermittent fasting plan did report slightly higher adherence rates than those assigned to the traditional diet. But participants’ responses at the completion of the study are telling. Only 58 percent of those on the two-day partial fasting plan intended to continue their assigned diet after the trial ended. On the other hand, 85 percent of those following the continuous diet reported that they would stick with their plan. Don’t Overlook the Diet’s Drawbacks The truth is, fasting – even partial fasting, as in the case of these new diet plans – can be uncomfortable and difficult to sustain. Many people report feeling weak, dizzy, or fatigued when they slash their food intake to 500 or 600 calories a day. And dramatically reducing calories for a day or two can leave you feeling ravenous, which can lead to binging. Have you ever skipped meals or vowed to eat really lightly one day, only to find yourself going whole hog at the end of the day because your stomach is gnawing at itself – or you just can’t stop thinking about food? This sort of on-off diet mentality can be especially problematic for people who struggle with emotional eating. If things get out of control, it can fuel a vicious cycle of restricting and overeating that often leads to weight gain – and an unhealthy relationship with food. The 2-Day Diet approach has other disadvantages. Not only are the calorie totals and portion sizes fluctuating from day to day, but so is the eating style. One day you’re doing low-carb, the next Mediterranean. Now imagine trying to keep your food plan straight while trying to balance work, family, and other responsibilities…and maintain a social life. Weight loss just doesn’t need to be this complicated, and it’s this type of unnecessary frustration that makes dieting seems so impossible when it really can be very manageable and realistic. What’s more, for some, the 2-Day Diet may not even create a large enough calorie deficit to support steady weight loss. Some middle-aged women, particularly those who aren’t very active or don’t have much to lose, need to limit themselves to 1,200 calories a day to successfully slim down. Cutting calories to 1,000 two days a week – and eating “regular” portions the rest of the week – may not be sufficient to move the scale. If you cut enough calories, there’s no question that intermittent fasting can lead to successful weight loss, at the least in the short term. But for many people, it’s a difficult eating pattern to sustain for more than a few weeks or months. If you do choose to give intermittent fasting a try (and you cleared it with your doctor), you could probably do it on your own, without the help of a diet book. Follow a healthy, balanced meal plan with plenty of vegetables, fruit, lean proteins, whole grains, and other nutrient-dense foods, and instead of trimming your calories moderately every day, try cutting calories more dramatically two or three days a week. (To get a baseline, use this simple calculator to determine how many calories you need to maintain your current weight – then subtract from there.) But make sure you take your personality into account when making a decision. If you know from experience that overly restricting yourself has negative repercussions (for many, it does), I strongly recommend adopting a more traditional approach, shaving a bit each day. By Johannah Sakimura
Posted on: Fri, 26 Jul 2013 19:13:44 +0000
Trending Topics
Recently Viewed Topics
© 2015