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
This dark, leafy green has a long list of benefits: it's a rich source of iron, folic acid, vitamin K, vitamin C, lutein, and powerful antioxidants that can help fight diseases like ovarian and breast cancer. Spinach is also loaded with magnesium, which can lower blood sugar and insulin levels (aiding your body in weight loss as a result), according to a 2013 study.
These foods—notably vegetables, fruits, legumes, and whole grains—should supply about 20 to 35 grams of dietary fiber a day, depending on your calorie needs. (Aim for 14 grams of fiber for every 1,000 calories, as advised by the Dietary Guidelines for Americans.) Fiber slows the absorption of carbohydrates, so they have less effect on insulin and blood sugar, and it provides other health benefits. Try to fill three-quarters of your plate with produce, legumes, and whole grains—leaving only one-quarter for meat, poultry, or other protein sources.
Is there anything avocados can't do? This creamy superfood (loaded with monounsaturated fats, potassium, magnesium, folate, and vitamins C and E) has been linked to improved vision, good heart health, and a reduced risk of certain cancers. And avocados can also help whittle your middle: according to one study, people who regularly consume them weigh less and have smaller waists than those who do not. Another study found that women who eat half an avocado at lunchtime might experience reduced food cravings later in the day.
Another weight-loss-friendly substitute to keep in mind is favoring salsa over ketchup. While ketchup typically has around 19 calories and 4 grams of sugar per tablespoon, fresh tomato salsa has about 5 calories per tablespoon, no added sugar, and is packed with nutritious veggies. Tomatoes, for example, are loaded with fat-blasting fiber and vitamin C, a deficiency of which Arizona State University researchers associated with increased body fat and larger waists. If you can handle spice, toss some jalapenos in your salsa to rev up your metabolism. For more on how you can switch your metabolism into overdrive, check out the best ways to boost your metabolism!