This diet eliminates all processed foods, refined sugars, grains, legumes and limits fruit for 30 days. If at any point you eat something you're not supposed to, you have to start the 30-day reset over.

Pros: "It's great to use as an elimination diet and getting yourself to consume foods in their natural state," Davis says.

Cons: "It's restrictive — even just for 30 days — making it hard to eat at a majority of restaurants, so dieters must do a lot of home cooking and prep to be successful," Davis says. "It also eliminates foods like whole grains, legumes and limits fruit."

Image via @whole30

"What you can eat is based on points: the amount of food and their respective points are based on unspecific parameters including age, weight, height and gender," Zembroski explains.

Pros: "High-sugar and unhealthful foods have high points value, while healthful foods, including fruits and vegetables, have no points," Zembroski says.

Cons: "You can eat anything you want on Weight Watchers as long as you account for it. This is a major issue as people may eat their points from nutrient-absent processed foods that increase the risk of developing blood-sugar issues, systemic inflammation and disease, as long as the points are accounted for," Zembroski says. He also notes that Weight Watchers bars and smoothies are loaded with processed and unhealthful ingredients, including high-fructose corn syrup, milk, soy protein isolate, artificial sweeteners, flavors and colors.

Image via @weightwatchers