Many people associate the term "low-fat" with health or healthy foods.
Some nutritious foods, such as fruits and vegetables, are naturally low in fat.
However, processed low-fat foods often contain a lot of sugar and other unhealthy ingredients.
Here are 10 low-fat foods that are bad for you.
In some ways, breakfast cereal appears to be a healthy way to start your day.
For example, it's low in fat and fortified with vitamins and minerals. The packaging also lists health claims such as "contains whole grains."
However, most cereals are loaded with sugar. In the ingredients section, sugar is usually the second or third item listed, meaning it's present in large amounts.
In fact, a 2014 report by the Environmental Working Group found that the average cold breakfast cereal contains nearly 25% sugar by weight.
Excess amounts of fructose have been linked to an increased risk of obesity, heart disease, kidney disease, type 2 diabetes and other health problems (1).
Additionally, the "healthiest" low-fat cereals may be some of the worst offenders.
Bottom Line: Low-fat, sweetened breakfast cereals are high in sugar, including "healthy" varieties such as granola.
Coffee is one of the healthiest beverages you can drink.
On the other hand, the high sugar content of flavored low-fat coffee drinks can negatively affect health.
For example, a 16-oz (450-gram) nonfat mocha drink has only 2 grams of fat but a whopping 33 grams of sugar. That's 57% of total calories (7).
Not only does this beverage provide a hefty serving of fructose, but it's in liquid form, which seems to be especially harmful to health (8).
Bottom Line: Adding sugar to coffee transforms a healthy beverage into one that may lead to weight gain and disease.
Yogurt has a long-standing reputation as a healthy food.
However, low-fat, sugar-sweetened yogurt contains too much sugar to qualify as a nutritious choice.
In fact, many types of low-fat and nonfat yogurt are as high in sugar as desserts.
For example, 8 ounces (240 grams) of fruit-flavored, nonfat yogurt contains 47 grams of sugar, which is nearly 12 teaspoons. In comparison, an equivalent serving of chocolate pudding has 38 grams of sugar (12, 13).
Bottom Line: Plain yogurt made from whole milk is healthy, but sweetened low-fat yogurt can be as high in sugar as desserts.
Salad dressing enhances the flavor of raw vegetables and may improve a salad's nutritional value.
Traditional salad dressings are high in fat, which helps your body absorb the fat-soluble vitamins A, D, E and K.
In contrast, low-fat and fat-free salad dressings don't contribute any health benefits to your meal.
Most of them also contain sugar and preservatives.
While it's no surprise that sweet dressings such as honey mustard and Thousand Island are high in sugar, many others are also loaded with sugar or high-fructose corn syrup. This includes fat-free Italian dressing.
Bottom Line: Low-fat and fat-free salad dressings contain sugar and additives but lack the benefits of healthy fats like olive oil.
Peanut butter is a delicious and popular food.
It's high in monounsaturated fat, including oleic acid, which may be responsible for many of the benefits.
However, note that natural peanut butter contains only peanuts and perhaps salt.
By contrast, reduced-fat peanut butter contains sugar and high-fructose corn syrup.
What's more, although the total fat has been reduced from 16 grams to 12, some of the healthy monounsaturated fat has been replaced by processed vegetable oil.
The calorie content of natural peanut butter and reduced-fat peanut butter is the same: 190 calories in 2 tablespoons. However, natural peanut butter is far healthier.
Bottom Line: Reduced-fat peanut butter contains sugars and processed oils yet provides the same number of calories as natural peanut butter, which is much healthier.
Low-fat muffins may seem like a healthier option than other baked goods, but they're really not any better.
However, this is a much smaller muffin than you'd find in a coffee shop or convenience store.
One group of researchers reported that the average commercial muffin is more than 300% larger than the USDA standard size (26).
With the exception of bran muffins, low-fat muffins contain little fiber and often have a high glycemic index (GI). High-GI foods raise blood sugar quickly, which may increase the hunger that drives overeating and leads to weight gain (27).
Bottom Line: Low-fat muffins are high in sugar and have a high glycemic index that may lead to hunger, overeating and weight gain.
Low-fat or nonfat frozen yogurt is considered a healthier choice than ice cream because it's much lower in fat.
However, it contains just as much sugar as ice cream, if not more.
What's more, portion sizes for frozen yogurt are typically much larger than those for ice cream.
Bottom Line: Frozen yogurt contains as much or more sugar than ice cream, and it's typically consumed in larger quantities.
Low-fat cookies aren't any healthier than other cookies. They're also not as tasty.
When the low-fat trend was at its peak in the 1990s, many low-fat cookies filled grocery store shelves.
However, researchers found that these low-fat versions were not very satisfying compared to the originals (30).Like most low-fat foods, the sugar content of these cookies is high. A fat-free oatmeal raisin cookie has 15 grams of sugar, which is 55% of its total calorie content (31).
In addition, low-fat cookies are typically made with refined flour, which is unhealthy.
Bottom Line: Low-fat and fat-free cookies aren't any healthier than regular cookies. They're very high in sugar and also taste worse.
Low-fat cereal bars are marketed as a healthy on-the-go snack for busy people.
In reality, they're loaded with sugar and contain very little protein, a nutrient that promotes fullness.
In fact, research shows that consuming high-protein snacks can help prevent overeating (32).
One popular low-fat, strawberry-flavored cereal bar contains 13 grams of sugar but only 1 gram of fiber and 2 grams of protein (33).
Bottom Line: Low-fat cereal bars are high in sugar but low in fiber and protein. In addition, they contain far more sugar than fruit.
Low-fat spreads such as margarine aren't a smart choice.
Even though they have less fat than original spreads such as butter, they still contain highly processed vegetable oils that can be harmful to health.
What's more, some of the light spreads specifically marketed as being "heart-healthy" actually contain small amounts of trans fats, which have been linked to inflammation, heart disease and obesity (34, 35, 36).
It's actually much healthier to use modest amounts of butter or healthy mayo rather than processed low-fat spreads.
Bottom Line: Low-fat margarine and spreads are highly processed. They are made with unhealthy vegetable oils and often contain trans fats.
Low-fat foods may seem healthy, but they're often loaded with sugar and other unhealthy ingredients. These can lead to excessive hunger, weight gain and disease.
For optimal health, it's best to consume unprocessed, whole foods. This includes foods that are naturally low in fat, as well as foods that naturally contain healthy fats.