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18 Ingredients That Nutritionists Say to Avoid Cooking With

Experts say that these cooking and baking essentials are weight loss saboteurs in disguise.

It may be better than drive-thru grub, but if you assume that cooking at home automatically guarantees a weight-loss-friendly meal, you've got it all wrong. In fact, with a cup of this and splash of that, you can transform a seemingly-healthy dish into one that will make the number on the scale soar.

To help you stay on track with your goal to slim down and get fit, we asked some of the top nutrition experts to reveal which common cooking and baking ingredients they wouldn't touch with a ten-foot pole. So neither should you! Read on to get in the know—and once you've tossed these out of your kitchen, be sure to check out these things healthy cooks always have in their kitchen so you can re-stock your cupboard like a pro. So that way you can try out these 21 Best Healthy Cooking Hacks of All Time, the right way.

Artificial Sweeteners

Artificial sweetener packets

"Although they don't contribute calories, artificial sweeteners are up to 700 times sweeter than natural sugar—and often leave you craving more sweets later in the day. If you're trying to cut calories from your baked goods, swap out sugar for unsweetened applesauce instead. One cup of the white stuff has more than 770 calories while the same amount of unsweetened applesauce has about 100. And better yet, a 1:1 ratio works perfectly! " — Alissa Rumsey, MS, RD

Cheap Vegetable Oils

Rapeseed canola oil

"Cheap oils like soybean, corn oil, and cottonseed oil are highly processed, contain high amounts of pro-inflammatory omega-6 saturated fats, and offer very little heart-healthy omega-3s. Instead of using these fats in your cooking, switch to avocado or coconut oil, which have both been shown to aid weight loss. Both oils have high smoke points, too, so they're great options for pan-frying." — Isabel Smith, MS, RD, CDN

"Eighty percent of the fat in palm kernel oil is saturated, and the cooking oil doesn't offer any real health-promoting properties. Instead, cook with oils that are made up of mono and polyunsaturated fats that have a medium to a high smoking point. Canola and olive oil both fit the bill." — Heather Mangieri, RDN

Fat-Free Dairy Products

Shredded cheese

"Although I'm a fan of fat-free milk, other fat-free dairy products like cheese, cream cheese and cottage cheese are a no-go in my kitchen. Many people find the texture, taste and mouthfeel of these products to be less satisfying, which either turns them off from the dish altogether or spurs cravings for seconds and thirds as they search for satisfaction." — Christine M. Palumbo, MBA, RDN, FAND

Looking for some healthy and delicious full-fat foods that will whittle your middle? Check out these 20 Best Full-Fat Foods for Weight Loss!

Food Coloring

Food coloring

"Artificial food dyes, which many people use to color baked goods, are cause for concern and may have serious side effects—especially in children. Red 40, for example, may contain cancer-causing contaminants, despite the fact that it's approved by the FDA. The dye may also be a potential trigger to hyperactivity in children. Instead, color your dishes with natural sources of color like beet juice, red cabbage or paprika." — Jay Cardiello, diet expert and personal trainer to the stars


Margarine stick

"Some margarine tubs contain heart-harming trans fats and are made with processed oils that may be pro-inflammatory. Inflammation has been directly tied to obesity, diabetes, heart disease, and cancer. Switch to grass-fed butter to pick up a product like Earth Balance that contains a mix of less processed oils." — Isabel Smith, MS RD CDN, founder of Isabel Smith Nutrition

Reduced-Fat Mayonnaise

Hellmanns mayonnaise
Warren Price Photography/Shutterstock

"Not only do low-fat foods not taste very good, but they're also filled with unhealthy and harmful ingredients like added sugars, vegetable oils, and artificial preservatives. These ingredients have little nutritional value and decrease the body's ability to absorb fat-soluble vitamins. Regularly eating things like low-fat mayo can lead to inflammation, GI issues, heart disease and increased cravings that lead to weight gain." — Stephanie Middleberg, RD, founder of Middleberg Nutrition

Conventional Peanut Butter

Spoon peanut butter

"Conventional peanut butter is filled with fully or partially hydrogenated oils, which are basically trans fats. Whether you're making peanut butter cookies or a Thai peanut sauce, use natural peanut butter that contains nothing more than peanuts and salt." — Isabel Smith, MS RD CDN

Not sure which jar contains the best nut butter? Check out our exclusive report, The 36 Top Peanut Butters—Ranked!

Bleached Flour

White flour and rolling pin

"Watch out for all-purpose flour that's been bleached. Although it may give your food a nicer color and help you to create baked goods that are more soft and tender, the bleach chemicals may be harmful to your health." — Jay Cardiello, diet expert and personal trainer to the stars

Gluten-Free Foods

Gluten free chocolate cupcakes

"Just because something is gluten-free doesn't mean it's calorie- or fat-free. If you have to eat gluten-free for medical reasons, that's one thing, but buying gluten-free products in an attempt to lose weight will not be effective." — Ilyse Schapiro MS, RD

Certain Milk Alternatives

Almond milk

"Carrageenan, a commonly used food additive, is an indigestible polysaccharide that is extracted from red algae and is commonly used in as a thickener or stabilizer in milk alternatives. Although it's derived from a natural source, carrageenan can be destructive to the digestive system, triggering an immune response that causes inflammation, gut irritation and lesions, and even cancer. While organic foods ban the use of GMOs, chemical pesticides, and toxic synthetic additives, carrageenan is currently still allowed, so it's important to check food labels." — Gina Hassick, RD, LDN, CDE

Quick-Cooking Oats

Quick Cooking Oats

"Oats are super healthful as they contain soluble fiber and minerals like calcium. Highly processed quick-cooking oats, however, are a different story. To make them cook faster, food manufacturers remove the outer layer of the oat which diminishes their nutritional value. If you're in need of a quicker-cooking oat for a recipe, try rolled oats. They go from stove to spoon faster than steel cut oats and contain more health-protective nutrients. — Isabel Smith, MS RD CDN

And speaking of delicious, healthy ways to eat oatmeal, check out these 50 Best Overnight Oats Recipes!

Flavored Yogurt

Flavored yogurt

"Sometimes 'healthy' dessert and smoothie recipes call for flavored yogurt. However, reduced-fat flavored yogurts are not a health food. Did you know that one container of flavored yogurt can have more sugar than a candy bar?! It's true! When you remove the fat from a naturally fatty food like yogurt, you have to make up for the taste by adding sugar, or worse, artificial sweeteners. And to make flavors like 'Apple Fritter' and 'Pineapple Upside Down Cake,' you're going to need to add a lot of sweetener. Instead, stick with organic, plain, full-fat yogurt." — Cassie Bjork, RD, LD of Healthy Simple Life

Corn and Simple Syrups

Corn syrup

"If a recipe calls for corn or simple syrup, use maple syrup or honey instead. While the former sugars are highly processed and contain little nutritional value, the latter options have antioxidants and antibacterial properties, all while providing the sweetness you're looking for." — Isabel Smith, MS RD CDN


Agave nectar

"Agave may be marketed as a healthier alternative to sugar. However, it contains more fructose than many other well-known sweeteners. This can be taxing on your cardiovascular system and increase your risk for metabolic syndrome." — Jay Cardiello, diet expert and personal trainer to the stars

Fat-Free Salad Dressing

Taco salad bowl

"Whether you use it as a marinade or dressing, fat-free salad dressing isn't a diet-friendly pick. It's often loaded with sugar, salt and artificial ingredients you wouldn't find in your kitchen. Plus, having a little fat with your vegetables can help you absorb more of the nutrients and antioxidants." — Christine M. Palumbo, MBA, RDN, FAND

Caged Eggs

Chickens in cage

"When you can, opt for pasture raised eggs over caged eggs. Pasture-raised chickens naturally have a more diverse diet, which means more nutrients, like omega-3 fatty acids, and vitamins A, D, and E are transferred to their eggs." — Stephanie Brookshier RD

Egg Beaters

Egg whites beaters

"Eggs that come out of a container are not a health food. Heat pasteurized and made from factory-farmed eggs, this product is processed so much that makers have to add in synthetic vitamins to boost its nutrient density. This is as far removed from a natural egg as you can get." — Dana James CDN, a nutritionist from Food Coach NYC

Canned Beans & Veggies

Canned soup

"Canned beans and veggies may help you get dinner on the table in half the time, but they can be spiked with salt and syrups. Also, the cans that these foods are stored in are often lined with BPA, a chemical that's been linked to cancer, infertility, and weight gain. Instead, look for products in tetra paks, or chop up fresh vegetables yourself." — Isabel Smith, MS RD CDN

Dana Leigh Smith
Dana has written for Women's Health, Prevention, Reader's Digest, and countless other publications. Read more about Dana Leigh