This Is the Absolute Worst Weight-Loss Mistake You Can Make

You've got slimming down on the mind, and you already know that eating veggies is the number one thing you should be doing to lose weight. But if you're new to this healthy lifestyle, you'll also need to know what mistakes you absolutely should not make — they could end up causing you to gain weight!

POPSUGAR Photography/Anna Monette Roberts

So we asked registered dietitian Leslie Langevin, MS, RD, CD, of Whole Health Nutrition to share the biggest mistake she sees people making when trying to drop pounds. Her answer? "Cutting out too much." Some people feel like they need to stop eating everything that's "bad" for weight loss, like bread or all carbs (even fruit), sweet treats, alcohol, meat, and/or dairy. While doing a diet reset by ditching processed and nutrient-void foods and switching completely to whole foods definitely has its benefits, "limiting to protein shakes and cutting out all carbs" doesn't work for long-term weight loss. Sure, a person will lose weight, but that kind of diet is impossible to sustain. As soon as you go back to eating all those delicious off-limit foods like cookies, ice cream, wine, and pasta, the weight will come back on, and the cravings and binge-eating can also come on strong.

Another form of this is eating super restrictive all week, and then once the weekend comes, going crazy and eating whatever you want. Leslie says, "A starved body during the week will hoard calories on the weekend if it is a normal pattern." If you try to be "good" all week by eating a diet that is completely deficient in all things tasty, you'll feel so deprived and depressed about it that you won't be able to control those natural cravings, forcing you to overindulge. You'll end up consuming way more calories than you would normally, which can make the scale numbers go up.

Eating healthy shouldn't be so black and white. Leslie suggests moderation, also known as the 80/20 rule. It involves eating clean and healthy 80 percent of the time, and then 20 percent of the time, you have the freedom to indulge a little. For those who eat three meals a day, it works out to about three "cheat" meals a week. This eating lifestyle works because as Jessica Alba's trainer Yumi Lee says, "You can't be 100 percent all of the time, but you can be 80 percent all of the time." Allowing you to satisfy cravings during the week translates to greater success in the long run, so this is a great way to have your cake, and lose weight, too.