Y. Wady Aude, MD; Arthur S. Agatston, MD; Francisco Lopez-Jimenez, MD, MSc; Eric H. Lieberman, MD; Marie Almon, MS, RD; Melinda Hansen, ARNP; Gerardo Rojas, MD; Gervasio A. Lamas, MD; Charles H. Hennekens, MD, DrPH, “The National Cholesterol Education Program Diet vs a Diet Lower in Carbohydrates and Higher in Protein and Monounsaturated Fat,” Arch Intern Med. 2004;164(19):2141-2146. http://archinte.jamanetwork.com/article.aspx?articleid=217514.
Cons: Teaching your body to burn fat instead of carbs takes time, so you have to be patient while you feel sluggish during the weeks it takes to become fat-adapted. And not every body burns fat as efficiently as carbs, so your endurance may never measure up (though, as we said before, others actually see an improvement here.) Without carbs, your body’s ability to generate explosive energy will most likely decline, so if you love sprinting or HIIT, you might need to consume more carbs than other low-fat dieters. And while you’ll probably lose body fat, this kind of diet is actually keeping you focused on the wrong macro: Studies have proven that the higher protein aspect of a low-carb diet helps promote weight loss, rather than the lower carb count.
Cons: That same study on the perks of being a keto athlete also found those same dieters had a lower exercise economy (how efficiently you use oxygen while moving). And whereas pretty much every other diet offers flexibility in the macro range, eating a few too many grams of carbs or protein will knock your body out of ketosis, so you have to be pretty committed to see the perks of this one. Lastly, the low protein count required to stay in ketosis may be holding you back here: A study analysis in Nutrition, Metabolism, and Cardiovascular Diseases found upping protein on a keto diet by just 5% tripled fat loss.
For even more impressive effects on body composition: aim for exercise forms which elicit a positive hormonal response. This means lifting really heavy things (strength training), or interval training. Such exercise increases levels of the sex hormone testosterone (primarily in men) as well as growth hormone. Not only do greater levels of these hormones increase your muscle mass, but they also decrease your visceral fat (belly fat) in the long term.
DASH was first introduced at a meeting of the American Heart Association in 1996 and later published in the New England Journal of Medicine in 1997.  The DASH trial randomly assigned 456 people to different diets to test the effects of dietary patterns on lowering blood pressure. The authors surmised that eating a diet with many different foods with blood pressure-lowering nutrients would show a greater effect on blood pressure than eating single nutrients, such as found in supplements or in a limited diet. Three diets were tested: 1) a control diet, or a standard American diet, 2) a fruits and vegetables diet, similar to the control diet but providing more fruits and vegetables and less snacks and sweets, and 3) a combination diet rich in fruits, vegetables, nuts, and low-fat dairy foods with reduced amounts of saturated fat, total fat, and cholesterol. The last two diets were richer in nutrients associated with lower blood pressure, such as potassium, magnesium, calcium, fiber, and protein. All three diets provided about 3000 mg sodium, which is more than the recommended amount from the Dietary Guidelines for Americans but less than the average sodium intake for Americans. 
The Mediterranean diet is most famous for its benefit to heart health, decreasing the risk of heart disease by, in part, lowering levels of “bad” LDL cholesterol, and reducing mortality from cardiovascular conditions. It’s also been credited with a lower likelihood of certain cancers, like breast cancer, as well as conditions like Parkinson’s disease and Alzheimer’s disease. (1)
What about fruits and vegetables? All fruits are rich in carbs, but you can have certain fruits (usually berries) in small portions. Vegetables (also rich in carbs) are restricted to leafy greens (such as kale, Swiss chard, spinach), cauliflower, broccoli, Brussels sprouts, asparagus, bell peppers, onions, garlic, mushrooms, cucumber, celery, and summer squashes. A cup of chopped broccoli has about six carbs.
People claiming huge benefits of these supplements – despite the lack of solid scientific support – may sometimes have a financial reason to believe in the supplements. Some of these products are sold under a multi-level marketing arrangement, where sales people are paid based on commission. For example, the company Prüvit sells drinkable ketones, called KETO//OS with a multi-level marketing structure.