The Skinny on Extreme Diets

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Extreme diets can be incredibly tempting for the millions of Americans who are looking to lose weight, fast. For people who are overweight or obese, weight loss can have countless health benefits, including lowering blood pressure and cholesterol, decreasing cancer, diabetes and heart disease risk, and even helping to slow or prevent dementia. As you all know, I am a firm believer that weight loss is an important health goal, but I also believe there are right and wrong ways to go about it. And the wrong ones aren’t just wrong – they can also be dangerous.

On my show, I’m going to talk about one of the newest extreme diets making the rounds: the five bite diet. The main principle of this diet, which was developed by Dr. Alwin Lewis, is that you can eat anything you’d like – but only for five bites, twice a day. Dr. Lewis suggests that this adds up to about 800 calories a day, which is less than half of generally recommended amounts, even for people trying to lose weight. Moreover, he suggests that people use this diet to attain a body mass index of 18.5, which is the very lowest BMI you can have without being considered underweight. This recommendation is based on studies mostly in animals that suggests that severe caloric restriction may help animals live longer and stave off certain diseases. You can learn more from Dr. Lewis about his diet by tuning in to my show.

I have several concerns with this kind of extreme approach to weight loss – the most important of which is that it almost entirely overlooks nutrition. Though Dr. Lewis suggests people take a multivitamin and make sure their 10 daily bites includes at least some protein, this is simply not enough to get people all the vitamins, minerals and other nutrients they need to support all the functions that the body needs to perform on a daily basis. In a healthy, balanced diet, you get calcium, magnesium, fiber, anti-oxidants, fat, omega 3 fatty acids and iron – among many other nutrients. In the five bite diet, you could eat pizza for each meal, and essentially nothing else. You’d be missing out on the vast majority of nutrients that keep you healthy and allow you to feel your best.

This is certainly not the only extreme diet out there, but many of them share a common goal: sudden weight loss and low target BMIs. Unless you’re naturally very thin (which is often attributable to genetics), it would be incredibly difficult to attain a BMI of 18.5. For example, if I were to aim for this BMI, I would have to lose 40 pounds and would ultimately weigh 140 pounds. As you know, I value my health incredibly highly and cannot imagine that this would be either safe or healthy for me. I also worry that diets like this one may encourage or even promote serious health conditions such as anorexia. We know that being underweight can carry its own significant health risks. In fact, one recent study found that people who are underweight with a BMI under 18.5 actually have a higher risk of dying than people who are obese.

One principle that some extreme diets, including this one, do get right, is that paying attention to what you eat, watching your portions and taking the time to eat slowly and savor what you’re tasting is a good way to lose weight and enjoy your food more. But the good news is that you don’t need extreme diets like these to lose weight (plus, you can skip the headaches and fatigue that often come with this kind of deprivation). Study after study has shown that well-balanced (and delicious) diets like the Mediterranean diet and the DASH diet not only help people with safe weight loss, but also dramatically decrease the risk of cancer, heart disease, diabetes and dementia, among other diseases. You can learn more about these healthy and nutrient-rich diets here and here. And when it comes to diets, being healthy – not rail-thin – is the most important thing. The right diet for you will help you to attain your weight-loss goals while still keeping you well-nourished and happy.