Vegetarians are generally thinner and healthier than meat-eaters, according to a 2013 study published in the American Journal of Nutrition and Dietetics. While going totally vegetarian may not be realistic for you, one way to slim down your meals is to replace some meat with plant protein. Black beans, for example, give you 15 grams of protein per serving, and mushrooms are rich in umami flavor, and can be used to replace half the ground beef in most recipes.
Sodas and juices are essentially liquid candy: They contain up to 18 teaspoons of sugar and upwards of 240 calories per 20-ounce serving, and provide zero nutritional value. Experts point to soda as one of the top contributors to the obesity epidemic. Diet drinkers aren't off the hook, either. A study in the journal Obesity found that diet soda drinkers were more likely to have a high percentage of fat in their bellies. Researchers believe diet drinkers may overestimate the calories "saved," and then overeat.
Try upping your fiber intake—it may work just as well as following a strict diet. In an American Heart Association study, one group was instructed to follow a diet with strict nutrient goals and limits on calories, sugar, and saturated fat, while the other group was given one goal: consume 30 grams of fiber a day. At the end of the 3-month study, both groups lost weight and improved their heart health, showing that losing weight may be as easy as filling up on more fiber.
Fresh, in-season produce gives you the biggest nutritional boost, but frozen veggies come in a close second. Very shortly after being picked, these fully ripe veggies are frozen, allowing them to lock in many of their nutrients. Having a stash of veggies in your icebox makes healthy eating on the fly oh-so-easy—and reduces the chance you'll order in a pizza.
Better yet, replace all refined grains with whole. People who eat a lot of whole grains are more likely to keep their weight down than those who eat refined grains. In one study, women whose diets contained the most wheat germ, brown rice, dark bread, and popcorn had a 49% lower risk of major weight gain over time.
Making meals from scratch is time-consuming, sure, but relying on frozen dinners and other packaged products won't help you out in the long run. One recent study found that we burn 50% more calories metabolizing whole foods than processed foods. So not only are you likely to decrease your calorie intake when prepping your own meals, your body will thank you with a metabolism boost.
Capsaicin, the compound in chili peppers that makes them hot, may speed up your metabolism, according to a study in Physiology & Behavior. Researchers say capsaicin activates your sympathetic nervous system, and that the effect on metabolism can last for more than 4 hours after eating.
You should largely avoid snacks that come in a bag or box. When you do want to indulge, measure out a serving rather than eating out of the package. Researchers from Cornell University found that people ate 50% more chips when they were given no visual cues to how large a portion should be.
When you make purchases with a credit card, you only realize how much money you're spending in a conceptual sense—you don't actually see the cash coming out of your wallet. According to a study in the Journal of Consumer Research, that may lead you to buy more unhealthy, calorie-dense foods despite the extra cost (both money-wise and diet-wise). Researchers believe credit cards make it easier to make impulse buys.