You Should Actually *Avoid* “Sugar-Free” and “Fat-Free” Foods When You’re Trying to Lose Weight — Here’s Why

We’ve all seen them on the supermarket shelves: lower-calorie versions of our favorite foods, like fat-free salad dressings and sugar-free peanut butter cups. But these products, which are typically marketed as “healthier” choices, can actually be a trap. As it turns out, the best things in life aren’t always free.

Here’s why “sugar-free” and “fat-free” foods can be an issue

The reward system in our brains activates every time we do something we perceive as pleasurable or rewarding. Essentially, when we eat something that tastes good or we do something that we perceive as fun, we release dopamine, aka “the feel good hormone.” 

Relatedly, when we eat foods we find pleasurable, our brains give us a food reward, and this reward trigger is something we all subconsciously strive for when we eat; in fact, it’s what allows us to feel satisfied. This is why packaged sweet treats like sugar-free Jello and sugar-free Peeps may be problematic: although artificial sweeteners provide a sweet flavor similar to sugar or honey, there is evidence to suggest that the lack of calories in reduced-fat and low-calorie foods prevents the complete activation of our food reward pathways. Several recent studies have shown that this may be one reason that sugar-free foods may actually cause weight gain, not weight loss. 

Similarly, whole foods labeled as fat-free may be generally lower in calories and fat, but they are also often loaded with additives, sugar, and fillers that make them less healthy. Popular grocery items like fat-free ranch dressing and low-fat cheese may seem to promote a healthy alternative to your staple items, but that’s not the case. 

The idea of low fat-diets is a fairly recent one. The low-fat diet trend started in the 1960s for patients with a high risk of heart disease and promptly swept the nation, (hopefully) peaking in the 1990s. But although many people subscribe to the idea that a low-fat diet is more heart-healthy, there’s no clear evidence supporting this — especially when compared to diets that incorporate healthy sources of fat, like olive oil, which have been linked in studies to a reduced risk of heart disease. The reality is that most foods that are marketed as “low-fat” versions of naturally higher-fat foods contain possible disease- causing ingredients such as high fructose corn syrup, unsaturated vegetable oils, and trans fats. 

“If I see a health claim on a food, that makes me want to take a deeper look at the ingredient profile,” says Blake Butler, DC. “Terms like ‘fat-free’ or ‘low-calorie’ often indicate that there are additives or fillers that you wouldn’t necessarily find in your grandmother’s pantry.” 

These foods can have some concerning long-term effects

Many people take the stance that if they are trying to lose weight for a short period of time, it’s not harmful to eat prepackaged sugar-free and low-fat foods. And the truth is, if you’re eating foods that are high in chemical fillers for a few weeks, you probably will be fine. But the reality is that these treats can create habits that we tend to stick to for far longer than a few weeks. 

While artificial additives have to meet pretty strict standards under the Food and Drug Administration (FDA), there is debate on whether those standards are strict enough and what the long-term effects are of consuming these filler ingredients. 

“In many cases, fat-free foods contain added sugar or added ingredients that aren’t necessarily beneficial to our gut health or our brain health,” says Butler. “We can also see artificial food coloring, sodium nitrate, and artificial sweeteners that can have a negative impact on our gut microbiomes, which can impact how we respond to food, which has an impact on hormonal trends and blood sugar regulations. It creates a vicious cycle of how our body responds to food in the long term, although we may be reducing calories in the short term.” 

While the gut microbiome may not seem to have anything to do with weight loss, that couldn’t be farther from the truth. Your gut microbiome is the bacteria that allows your body to absorb nutrients through your intestines. When you intake ingredients such as artificial sweeteners, some long-term studies show that the consumption of artificial sweeteners change the composition of the gut microbiota and may contribute to the development of metabolic derangements that lead to obesity, type-2 diabetes, and cardiovascular disease. 

Other recent studies are also beginning to show that our gut may have a direct impact on nutrient metabolism and energy expenditure which leads to weight gain and affects individuals ability to lose weight. 

Here’s the best strategy for healthy weight loss 

Some diets can be extremely restrictive, and we’re honestly not major fans of those. It’s important to keep eating plenty of nutritious whole foods, whether or not weight loss is your goal. They’re essential for enhancing your overall nutrition by giving you the nutrients, vitamins, minerals, protein, and fiber you need to be your healthiest self. 

While highly processed reduced-fat and sugar-free foods may seem more convenient when you want to lose weight, they are often low in nutrients and packed with unnecessary and harmful ingredients. Instead, we’d suggest enjoying all the foods you normally enjoy, just in small portions. So rather than buying fat-free cheese or sugar-free chocolates in a bid to lose weight, instead enjoy a smaller portion of real cheese, and some high-quality dark chocolate, too. We’d recommend ideally swapping refined sugar for options like maple syrup or honey, and enjoying lots of fresh fruits to satisfy the sweet tooth craving as much as possible. 

When trying to lose weight, the best idea is to stick to whole, unprocessed foods, like fresh vegetables, fruits, lean proteins, healthy fats, and whole grains. This way, you can make sure you’re getting all the vitamins and nutrients you need, rather than buying into the low-calorie, fat-free, and sugar-free options that you see at the grocery store. They may or may not help you lose weight in the short term, and can cause an array of issues down the road, whereas whole foods will help you feel fuller longer and can help you fight off disease, too.  

Read next: What You Need to Know About the Gut Health-Sleep Connection