Stephen Colbert may be on to something. UCLA Center for Human Nutrition researchers divided study participants into two groups, each of which were fed a nearly identical low-cal diet for 12-weeks. The only difference between the groups was what they were given to eat as an afternoon snack. One group ate 220-calories of pretzels while the other group munched on 240-calories worth of pistachios. Just four weeks into the study, the pistachio group had reduced their BMI by a point, while the pretzel-eating group stayed the same, and their cholesterol and triglyceride levels showed improvements as well.
Good news for java lovers: The caffeine in coffee could speed up your metabolism and help your body burn slightly more calories (about 26 per cup). A study in Physiology & Behavior found that the average metabolic rate of people who drank caffeinated coffee was 16% higher than those who drank only decaf. Just be mindful of how much cream and sugar you add to your cup, which could offset any health benefits the beverage provides.
Popular diets, often referred to as fad diets, make promises of weight loss or other health advantages such as longer life without backing by solid science, and in many cases are characterized by highly restrictive or unusual food choices.:296 Celebrity endorsements (including celebrity doctors) are frequently associated with popular diets, and the individuals who develop and promote these programs often profit handsomely.:11–12