12 Foods That May Cause Unhealthy Weight Gain

2. Flavored yogurt

Even if it’s labeled “fat-free,” yogurt is a hidden source of added sugar. A 6-ounce container of chocolate nonfat yogurt contains 25 grams of sugar — more than an entire day’s worth for women. This doesn’t mean yogurt is unhealthy. Not only does it have protein and calcium, many yogurts have bacteria that are great for your gut health.

Tip: Rather than eat flavored yogurts that are packed with sugars, go for plain Greek yogurt and stir in fruit or a bit of honey. Yes, honey is a type of sugar as well, but it has numerous health benefits and is less processed than refined sugar. Just don’t overdo it: One teaspoon of honey has about 6 grams of sugar.

3. White bagels

This breakfast staple, especially in the white or plain form, is just one example of a simple carbohydrate that can spike blood sugar and contribute to excess fat storage. Muffins, cookies, white bread and cereal are other types of simple carbs.

Why do these foods cause weight gain? “One is the calories. If you’re eating more calories, you’ll gain weight,” says Adam Goldstein, M.D., director of the University of North Carolina Weight Management Program in Chapel Hill. A large bagel packs more than 360 calories. Add a schmear of cream cheese at 100 calories, and you’ve already consumed nearly a quarter of your daily allotment if you’re on a 2,000-calorie diet. The second reason is the quick-digesting nature of simple carbs. They leave you feeling hungry sooner, leading to overeating, says Goldstein.

Tip: If you need a bagel fix, look for one made from whole wheat or whole grains and consider having just half, with fresh fruit on the side.

4. Red meat

Before you order a side of bacon to accompany your eggs or dig into a T-bone steak, consider this: A study that followed the diet and exercise habits of more than 120,000 people for up to 20 years linked processed and red meat to one pound of weight gain every four years (in addition to weight gain from other foods). Meat is particularly problematic for putting on pounds because it contains protein and saturated fat, both of which promote weight gain.

That’s not the only bad news about meat. “Too much animal protein has also been scientifically linked to inflammation in the body, which can also cause weight gain,” Richter says.

Tip: If you reach for red meat go for a lean steak or burger. Otherwise, treat red meat as sideshow to your diet and not the main attraction, she adds.

5. Fried fish

Fish like salmon, tuna and shrimp are high in heart-healthy omega-3 fatty acids, low in saturated fat and high in protein. However, when you dredge your fish in flour and deep fry it in hot oil.  you’re adding calories and unhealthy fat, which can contribute to unwanted weight gain

Tip: Rather than fry fish, bake, broil or grill it to get the numerous health benefits.

6. Plant-based dairy foods (with added sugar)

Avoiding dairy is fine, especially if you’re lactose-intolerant, but be cautious of plant-based substitutes like cashew, almond or coconut yogurt, ice cream and milk. “My patients are trying to make healthy swaps. They think they’re doing the right thing, but they’re just trading one evil for another,” Richter says.

Because plant-based foods don’t have the same texture and flavor as dairy, manufacturers add sugar to compensate, contributing to fat gain. 

Tip: Look for the unsweetened versions of plant-based dairy products to cut down on added sugar.

7. Sodas, alcohol and other sugary drinks

It might be easy to connect the contents of your plate with the higher numbers on your scale, but what’s in your glass also factors into your weight-loss struggles. Regular sodas and other sugary beverages are one of the biggest culprits when it comes to excess calorie intake.

When you order your Starbucks coffee with extra cream and lots of sugar, “now it’s basically like a chocolate bar,” says Richter. Even diet soft drinks are linked to weight gain, possibly by making you crave more sugary, high-calorie foods.

Some drinks hide under the guise of healthfulness, like kombucha. It seems like a healthy beverage option — after all, it’s made with fermented tea. In reality, “it has a ton of added sugar in it,” says Richter. Many fruit and vegetable juice drinks also contain lots of sugar. If you are watching your weight, eat an orange or an apple instead of drinking orange or apple juice.  

Alcoholic drinks are double offenders, especially mixed drinks. A piña colada packs a whopping 245 calories and 31 grams of sugar. Alcohol also promotes inflammation, which contributes to weight gain.

Tip: Stick to water, unsweetened tea or black coffee. For some extra flavor, throw a lemon, mint or berries into your drink. 

8. Nuts

These foods constitute a whole different type of fat — the mono- and polyunsaturated kinds that are rich in antioxidants and have anti-inflammatory properties. They’re good for your health and therefore worthy of eating.

But because they’re high in calories per ounce, you’ll want to eat these healthy fats in moderation to avoid weight gain, says Spiegel. 

Tips: Stick to small servings, like one tablespoon of peanut butter or a handful of nuts—not the whole jar.

9. Olive oil

While olive oil is a great choice for cooking and dressings, a little goes a long way—one tablespoon has just over 100 calories.  “Since it has plenty of benefits, it’s still an important part of our everyday diet - but best to use it as a drizzle rather than a glug if you’re focused on weight,” says Rachel Gargano, chief registered dietitian at Live it Up and a nutritionist with board certifications in sports dietetics and breastfeeding.

Tip: Use a measuring spoon instead of eyeballing your pour to keep portions in check. 

10. Smoothies

Smoothies can be a great way to pack in nutrients, but they’re also an easy place to rack up extra calories. Too much nut butter, chia or flax seeds, added sugar, or a high-fat base can turn a healthy smoothie into a calorie bomb. 

“The body doesn’t recognize liquid calories the same as eating solid foods, it can be easier to drink more calories than what the body needs,” says Gargano

Tip: Use a protein-rich base like Greek yogurt or unsweetened milk and balance your smoothie with fiber-rich ingredients like berries or spinach to help keep you full. 

11. Salads

Salads can be loaded with fiber, antioxidants, vitamins and minerals—but what you put on them matters. Piling on cheese, bacon bits, croutons or creamy dressings can pack more calories than you expect. 

Tip: Keep your portions in check when using calorie-dense toppings and opt for a light vinaigrette instead of creamy dressings. For an even bigger nutritional boost, go for a variety of colorful veggies and lean proteins to keep you full. 

12. Low calorie ultra-processed food

While it may be obvious that packaged cookies, chips, and fast food should be avoided, frozen meals—even the ones labeled “low calorie”—fall into the ultra-processed category too.

Most ultra-processed foods are loaded with added sugars, unhealthy fats, and sodium, but there’s another issue: how the body processes them.

“The processing makes it easier for our bodies to absorb more calories than from whole foods, and they require fewer calories to digest, which makes overeating more likely," she says.

Studies show people who eat more ultra-processed foods tend to eat much more calories per day than those stick to a diet richer than whole foods.

Tip: Instead of frozen meals, try meal prepping and keep ready-made healthy meals in your freezer. And when it comes to snacks on-the-go reach for fruit or plain yogurt instead of chips. 

Focus on the big picture

Eating a high-fat or sugary food once in a while isn’t going to lead to weight gain. It’s more about the quality of your diet as a whole, says Dr. Goldstein.

Fill your plate with nutrient-dense foods like lean proteins, nonstarchy vegetables and fiber-rich fruits to help reduce calorie intake without feeling deprived

“We don’t want people to restrict, thinking, I can’t have this,” he adds. “You can have almost anything you want, in moderation.”

Bottom line: Eating more of the foods that won’t make you gain weight, like nonstarchy vegetables and berries, will leave less room for foods higher in calories, saturated fat and added sugar. Remember that your diet should be not only healthy, but also sustainable. “That’s the real key,” says Goldstein. “Anyone can lose weight. The question is, can anyone keep weight off?"