"There is promising research on effective weight loss from intermittent fasting, an eating strategy where you eat very few calories two days per week while eating higher calorie levels the remainder of the week. However, this form of eating involves careful planning to ensure every calorie consumed on ‘fasting’ days is nutritionally dense. I would encourage someone interested in the Military Diet to consider this weight loss strategy before following this diet plan. Fad diets don’t work — whatever you do to lose weight has to be something you can see yourself following for life. If it is too restrictive, you will just regain the weight."
The popular low-carb diets (such as Atkins or Paleo) modify a true keto diet. But they come with the same risks if you overdo it on fats and proteins and lay off the carbs. So why do people follow the diets? "They're everywhere, and people hear anecdotally that they work," McManus says. Theories about short-term low-carb diet success include lower appetite because fat burns slower than carbs. "But again, we don't know about the long term," she says. "And eating a restrictive diet, no matter what the plan, is difficult to sustain. Once you resume a normal diet, the weight will likely return."

“Crash diets, also called meal-replacement programs, have become increasingly fashionable in the past few years,” said lead author Dr. Jennifer Rayner, Oxford Centre for Magnetic Resonance, University of Oxford, Oxford, UK. “The metabolic improvements with a very low-calorie diet, such as a reduction in liver fat and reversal of diabetes, would be expected to improve heart function. Instead, heart function got worse in the first week before starting to improve.”
"When going out for fast food, I used to get the large-size value meal. Now, I satisfy a craving by ordering just one item: a small order of fries or a six-piece box of chicken nuggets. So far, I've shaved off 16 pounds in seven weeks, and I'm on track to being thinner than my high school self for my 10-year reunion later this year." —Miranda Jarrell, Birmingham, AL