Like protein, fiber slows the rate at which your body plows through carb calories so you feel full for longer and maintain steadier blood sugar levels, one reason why research consistently links fiber intake to weight loss. That means fibrous whole grain bread tends to be a better choice than white bread and also explains why fruits, which contain fiber and valuable vitamins in addition to sugar, beat straight-up candy every time.
Variety: Nobody wants to eat the same thing day in and day out. That's why a variety of food items is essential for a diet plan to be sustainable. Also, variety as a criterion for determining the best diet plans refers not only to food items but also to groups of people. For example: Is the diet plan available to diabetics? Men? Women? People with allergies or special conditions?
"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
This popular diet program is fairly restrictive — and for the first 30 days, dieters must cut out grains, legumes, most dairy, added sugar, and alcohol without any slip-ups, according to the Whole30 website. (29) The aim is to “reset” your body and to adopt dietary habits resulting in weight loss. Cutting out added sugar and alcohol has merit, but all the restrictions prove challenging and could lead to nutrient deficiencies and disordered eating.
Based on the concept of caloric density, which states that some foods have few calories in proportion to their size (say, a lettuce), while others have lots of calories packed in small portions (a regular chocolate chip cookie comes to mind), Volumetrics divides foods into 4 categories based on their calorie/volume ratio, and is perfect for people looking to binge on some foods while still shedding pounds. However, as with the calorie counting approach, Volumetrics does not take into account the quality of the calories, prioritizing quantity instead. The app Noom and Weight Watchers (both reviewed above) share similarities with this diet theory.