We reached out to two experts to see what they thought — and if the diet works. "It’s a low calorie diet that includes typical American foods," said Janis Jibrin, MS, RD, an adjunct professor of Nutrition at American University. "It’s nutritionally deficient, but not as crazy as some (i.e. juice fasts)." When it comes to the meal plan, she's not a fan. "It’s too low in many nutrients," she explains. Day 2 alone is "so low in fiber, iron, calcium and other nutrients, yet it manages to hit the daily sodium max. (Actually, most health authorities recommend 2,300 mg as a max, so this diet exceeds it.) Sure, the other four days offer more calories and nutrients, but even so, you’re still skimping."
It’s impossible to target belly fat specifically when you diet. But losing weight overall will help shrink your waistline; more importantly, it will help reduce the dangerous layer of visceral fat, a type of fat within the abdominal cavity that you can’t see but that heightens health risks, says Kerry Stewart, Ed.D., director of Clinical and Research Physiology at Johns Hopkins.
Sleep enough – for most people at least seven hours per night on average – and keep stress under control. Sleep deprivation and stress hormones raise blood sugar levels, slowing ketosis and weight loss a bit. Plus they might make it harder to stick to a keto diet, and resist temptations. So while handling sleep and stress will not get you into ketosis on it’s own, it’s still worth thinking about.
If you've seen the TV show, you get the idea: Six weeks of healthy food and regular exercise is celebrated as a great start to a weight-loss journey – as well as a way prevent or reverse various diseases. Fair enough. Experts determined that the Biggest Loser Diet is very likely to help you shed pounds, thanks to calorie restriction and exercise. To reap the other benefits of weight loss, however, you have to stick with it – something that's a lot harder for average Joes than for TV stars-in-the-making.
Carbohydrates are a touchy subject: while some blame them for all fat gain, it’s the type of carbs you eat that’s key. A 2011 study out of the University of Alabama found that a diet that slightly cut back on carbs, and which comprised mostly low-GI carbohydrates, lost more deep abdominal fat than those who ate a lower-fat diet. GI stands for glycemic index, a measure of how fast carbohydrates supply your body with energy: high-GI foods make you spike then crash, while low-GI foods provide a slow burn.
Another difference between older and newer studies is that the type of patients treated with the ketogenic diet has changed over time. When first developed and used, the ketogenic diet was not a treatment of last resort; in contrast, the children in modern studies have already tried and failed a number of anticonvulsant drugs, so may be assumed to have more difficult-to-treat epilepsy. Early and modern studies also differ because the treatment protocol has changed. In older protocols, the diet was initiated with a prolonged fast, designed to lose 5–10% body weight, and heavily restricted the calorie intake. Concerns over child health and growth led to a relaxation of the diet's restrictions. Fluid restriction was once a feature of the diet, but this led to increased risk of constipation and kidney stones, and is no longer considered beneficial.
I know it's cliché, but let me get specific: When I arrive at a party, I don’t go immediately to the food. I first think about how many hours I plan on being there and try to pace myself accordingly. If I know it’s a three-hour buffet dinner, I may not start eating until an hour into being there. I’ll focus on drinking lots of water first and talk to people, so I don’t stuff my face too early and overdo it.