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10 Mistakes Diet Experts Say You're Making—And How to Fix Them

The first "diet" ever recorded was a fatal flop.

William the Conqueror, so fat he could no longer ride his horse, took on a "liquid" diet, attempting to subsist on nothing but alcohol for the better part of a year in the name of weight loss. Amazingly, he slimmed down a bit and was able to get back on his horse. Unfortunately, he had a bit of trouble staying on the saddle and died of complications by falling off it—talk about a crash diet! To add insult to injury, courtiers had to "squeeze" his still very overweight body into a casket.


That was back in 1087. And so began the centuries-long story of failed weight loss attempts. In fact, a recent systematic review of 898 weight loss papers found an average 30 percent of dieters drop out of structured programs, and only 15 percent are "successful," maintaining a weight loss of at least 20 to 24 pounds for three years or more.

That means a paltry 15 out of 100 of us will actually succeed at losing the weight and keeping it off. Where do we go so wrong? We reached out to leading dieticians from across the country—the experts that work with dieters on a daily basis, to find the number one mistake they see clients make, and how you can avoid the pitfall.

P.S. The "alcohol diet" is still not a good idea.

You Think Calories Are King

Man counting calories

"It's important to have overall health as the main goal. Otherwise, when weight loss is the only goal, I see people focusing on calories above all else and, often times, favoring highly processed, minimally nutritious foods (i.e. pretzels, fat-free Cool Whip, baked chips) over healthier whole foods that may be more caloric, but are nutritious and filling (i.e. almonds, avocados)." – Andy Bellatti, MS, RD, Dietitians For Professional Integrity

You Become Paralyzed by Perfection

Woman worried about her gym results

"People tend to set big, monstrous goals that would be hard for even the most disciplined person to achieve. Things like 'cut out all sugar' or 'go to the gym every day.' When I worked in weight management, I would have clients make a list of three goals and then we'd downsize them significantly. The point was that it feels awful to "fail" at a goal. But it feels fantastic to achieve that goal, even if it's very small. Then once you achieve it, you can build on it. So instead of vowing to 'go the gym every day,' set a goal that seems (on paper at least) almost too easy—like doing a once- or twice-weekly workout. Do that for a few weeks until it's routine. Then add a third day, or add a walk around the neighborhood after dinner once a week. The point is to slowly build habits that will eventually feel natural, just a part of life, not a struggle you're making in the name of losing weight." – Sally Kuzemchak, MS, RD, Blogger at Real Mom Nutrition, Author of Cooking Light Dinnertime Survival Guide.

You Put Foods on a Naughty List

Woman choosing apple over sugar-filled pastry

"Often times, people will go 'on' a diet and swear they'll never eat their favorite foods ever again. No more birthday cakes, cookies, pizza, alcohol, etc. Then, the second they eat one thing that's on their "never eat again" list, they're set completely off track, think there's no hope and beat themselves up. Diets are not all-or-nothing. Diets are the foods that fuel your body each day. Want sweets? Great, enjoy them—not an entire sleeve of cookies or pint of ice cream, just a portion; then put them away." – Christopher Mohr, PhD, RD, Nutrition Consultant at Mohr Results

You Restrict and Repeat

Hungry woman skipping meal

"Skipping meals or undereating is the most common mistake I see among clients. And binge eating after a majorly unsatisfying and calorie deficient day isn't uncommon. Start your day strong with a protein- and veggie-rich breakfast (something all Americans need to work on), and have a plan for lunch: find a go-to healthy item to order, or pack your own." – Carlene Thomas, RDN, Author of The Wedding Wellness Workbook: Your Nutrition How-To Before 'I Do.' And burn fat before waking up by making any of these essential 50 Best Overnight Oat Recipes!.

You Try to Go Solo

Woman walking in park
Arek Adeoye/Unsplash

"Weight loss isn't about willpower, it's about having a plan and enlisting support. I encourage my clients to plan their meals in advance (before hunger or cravings), identify a friend or family member to support their healthy habits and enlist the expert help of a Registered Dietitian and other healthcare providers as needed." – Lori Zanini, RD, CDE, Spokesperson for the Academy of Nutrition and Dietetics

You Rely on the Scale

Woman on scale upset

"The mistake I see most is setting overly ambitious weight loss goals. Just yesterday, I was setting January goals with clients. I asked, 'Do you have a number of pounds you'd like to lose this month?' Inevitably, many clients said eight—or even higher! 'What? Two a week, that's not unrealistic,' a client said. I explained it isn't unrealistic, but maybe you won't lose two every week. I would rather have a client set five pounds a month as the goal and feel successful versus 8-10 and feel like a failure. Success breeds success! Set your goal slightly lower and let yourself feel like you hit it." – Lauren Slayton MS, RD, Author of The Little Book of Thin, Founder of Foodtrainers

You're Tempted by an Unhealthy Pantry

Woman grabbing cookie from jar

"Cut the crap! Stock your kitchen with only healthy options. It makes the healthy choice not just the easy choice, but the only one." – Claudia Zapata, MS, RDN, Blogger at Pack your cart with any of these fast-blasting 50 Best Snacks for Weight Loss!

You Forget Family

People eating pizza

"If you don't change the food environment for the whole family, it's easy to fall back into old patterns. It's not fun to watch other family members eat takeout pizza when you're eating a microwave diet dinner. You have to cook 'real food' for the entire family." – Debra Riedesel RD, LD, The Cycle Diet for Women

You Munch When You're Moody

Sad woman eating ice cream

"Stay alert to an emotional set-up. If you have had a bad day at work, argument with a loved one, or are just feeling blue, expect that your emotions may try to convince you to take a detour from your healthy roadmap. Awareness is over half of the battle, so have an alternative activity or plan mapped out and ready." – Tammy Beasley, RDN, CEDRD, LD, Owner of RevItUP! for Life: Your Healthy Lifestyle Roadmap

You Totally Overhaul Your Diet

Woman barely eating cucumber

"Instead of trying to change all bad habits at once, a person can be way more successful if they try and tackle one at a time. For example, if you want to give up refined sugars, and cut back on fried foods and consume less alcohol, that could be really daunting. Instead commit to one, get used to it, see results, then move on to another." – Keri Gans, RDN, Author of The Small Change Diet

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