Recently, the Military Diet began provided scientific evidence to support their program. The problem is that the science is about other diets, not about this 3-day program. For example, the website cites research conducted by nutrition scientist Krista Varady. But her research was conducted to support her diet (The Every Other Day Diet), not the Military Diet. There is some science to support intermittent fasting, but none (that I've seen) to support a hot dog and ice cream based plan.
A meta-analysis of randomized controlled trials by the international Cochrane Collaboration in 2002 concluded[31] that fat-restricted diets are no better than calorie-restricted diets in achieving long term weight loss in overweight or obese people. A more recent meta-analysis that included randomized controlled trials published after the Cochrane review[32][33][34] found that low-carbohydrate, non-energy-restricted diets appear to be at least as effective as low-fat, energy-restricted diets in inducing weight loss for up to 1 year. These results can be understood because weight loss is mainly governed by daily caloric deficit and not by the particular foods eaten.[35] However, when low-carbohydrate diets to induce weight loss are considered, potential favorable changes in triglyceride and high-density lipoprotein cholesterol values should be weighed against potential unfavorable changes in low-density lipoprotein cholesterol values."[36]

"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