The Worst ‘Low-Calorie’ Foods That Spike Your Blood Sugar & Trigger Fat Storage: Low-Fat Yogurt, More
March 26, 2025 by Mariam Qayum
Low-calorie foods are often marketed as healthy choices for weight loss, but not all of them support balanced blood sugar levels or fat-burning. Some seemingly “healthy” low-calorie options can actually cause rapid spikes in blood sugar, leading to insulin surges that promote fat storage rather than fat loss. This happens when these foods are high in refined carbs, hidden sugars, or artificial ingredients that disrupt metabolism. Understanding which low-calorie foods may work against your weight loss goals can help you make smarter choices that support steady energy levels and long-term fat burning.
We checked in with health experts to discover the worst low-calorie foods you should avoid because they can trigger fat storage and raise blood sugar levels. According to them, low-fat flavored yogurt and diet soda are the ones to steer clear of. Read on to learn more.
1. Low-Fat Yogurt
Yogurt is a staple in healthy food. Studies show that plain Greek yogurt can help with weight management and they help improve digestion. And, while you may think that all low-fat yogurts (which are typically made with skim milk) are even healthier for weight loss, the sugar-sweetened varieties contain too much sugar to qualify as a nutritious option.
According to the United States Departement of Agriculture, just 1 cup (or 245 grams) of fruit-flavored, nonfat yogurt contains 31 grams of sugar. That's about as much as a cup (or 190 grams) of fattening banana pudding.
Lisa Richards, creator of the Candida Diet, says that while low-fat yogurt on its own probably won't cause weight gain, it depends on how much and what else you are consuming in your diet. "Yogurt is a nutritious food that can be part of a healthy and balanced diet, as it is a good source of protein, calcium, and probiotics," she explains.
"Low-fat yogurt can be a good option for people looking to reduce their overall calorie intake, as it typically contains fewer calories than full-fat yogurt."
"However, some flavored yogurts can be high in added sugars, which can contribute to weight gain and other health problems if consumed in excess," Richards continues. "Furthermore, weight gain occurs when there is a calorie surplus, which means consuming more calories than the body burns through physical activity and normal metabolic processes." That's why it's crucial to check the label. Pick yogurts that are low in added sugars and artificial ingredients.
2. Diet soda
Unfortunately, Richards confirms that diet soda can be just as bad as regular, sugary soda in different ways. That’s because, in place of sugar, the diet variety is loaded with artificial sweeteners, which come with their own share of health risks. That means what you save in calories, you lose in other areas of your health.
"While diet soda may be lower in calories and sugar than regular soda, it is not necessarily a healthy choice," Richards warns. "Artificial sweeteners, such as aspartame and sucralose, which are commonly used in diet soda, have been the subject of ongoing debate and controversy regarding their potential health effects."
She goes on to say that some of the risks associated with artificial sweeteners include weight gain, type 2 diabetes, and increased risk of certain types of cancer. Additionally, these sweeteners can take a serious toll on your gut health by disrupting the balance of bacteria in your gut microbiome, which, in turn, can impact practically every aspect of your wellness. What’s more, the sweet flavor of these artificial ingredients can still lead to increased cravings for actual sugar even more, resulting in overeating and, ultimately, weight gain.
All in all, Richards notes, "It's important to note that diet soda is not a healthy drink, and it should not be consumed in place of water or other hydrating beverages. It is also important to pay attention to the total amount of soda, including both regular and diet varieties."