This post has been updated since its original publication date of 12/12/2022 to include more expert insight.
Some unhealthy foods are no brainers to avoid when you’re trying to lose weight: fattening donuts, salty potato chips, greasy cheeseburgers. However, a few detrimental ingredients may be sneaking their way into your daily diet without a second thought. Eating healthy isn’t just about cutting out junk food; it’s also about making smart decisions when cooking your own meals, which is why it’s so important to be aware of which ingredients could be putting your goal weight at risk.
To discover some of the worst options out there, we spoke to health experts Lisa Richards, nutritionist and creator of The Candida Diet, functional nutritionist Amy Lippert, Rebecca Novak, a registered dietitian, and chef at the Hungarian Chef, Dr. Tez Pratap Singh, MD, and Krutika Nanavati, registered nutritionist and dietitian. They pointed out six in particular you should cut down on whenever possible: refined flour, refined sugar, cooking oils, trans fat, high fructose corn syrup, and artificial sweeteners.
1. Refined Flour
If you bake frequently, you likely go through a good amount of flour. However, Nanavati points out that you should be cautious of the refined variety because it can "sabotage your weight loss efforts." Yikes! This is mainly due to the fact that refined flour, like many processed ingredients, is "high in calories and has little nutritional value."
Additionally, another major risk of this ingredient is high blood sugar. Nanavati explains that "refined flour is higher on the glycemic index than whole wheat flour, meaning it raises your blood sugar levels more quickly. This can lead to increased hunger and cravings, and may contribute to weight gain," he warns. What's more, if you frequently indulge in foods made with refined flour, you're also putting yourself at a higher risk of type 2 diabetes and heart disease. "Instead, try using whole wheat flour or almond flour," Nanavati concludes.
2. Refined sugar
We probably don't have to tell you twice that sugar should be avoided for weight loss—but it's so important to call out when we're talking about the worst ingredients out there. "When you consume [sugary foods and drinks] they have a negative impact on blood glucose levels and will cause a spike, resulting in an immediate burst of energy followed closely with a crash as the body works to bring the blood glucose levels back to a safe level," Lippert warns. And those glucose spikes can be seriously detrimental to your weight loss goals. "High levels of glucose are damaging to the body, so in response to this spike, the body releases insulin, a hormone that is the key to opening up the door to our adipose tissue (fat) to store the glucose (as glucagon) in order to reduce the levels in our blood, leading to weight gain," she explains. For this reason, laying off the sweets is crucial if you want to see that number on the scale go down—or if you just want to keep your body healthy overall.
3. Cooking Oils
Another common ingredient that could be wreaking havoc on your body and slowing your weight loss progress is none other than infamous cooking oils. "Oils are among the worst ingredients to cook with if you're wanting to lose weight," Richards tells us. "This is because they are very calorie-dense and provide little in the way of nutrients the body actually needs. Essentially, they are empty calories."
Of course, it's very difficult to cut all oil out of your diet for good, as some recipes can't do without them. However, Richards notes that they're not always necessary, especially in the high amounts many recipes call for. "For instance, when sauteing vegetables recipes will typically call for oil of some sort, about 2 tablespoons. This can be avoided by replacing oil for water or a low-calorie sauce like liquid aminos or balsamic vinegar," she says. Noted!
There's a similar story when it comes to cooking oil sprays, which she explains contain unnatural additives such as lecithin, "which acts as an emulsifier and dimethyl silicone which is an anti-foaming agent." One exception is avocado oil, which makes a great replacement to your typical cooking oil spray.
Switching up your diet and cooking habits surely isn't easy. However, if you want to see the fastest weight loss results possible, some sacrifices may be in order. That's why, whenever possible, choosing healthy alternatives to fattening ingredients like these is always your best bet.
4. Trans Fats
Like refined sugars, trans fats are another processed ingredient that can lead to weight gain and chronic inflammation. Trans fat is a type of unsaturated fat that is found in processed foods like frozen pizza, microwave popcorn, French fries, and more. Eating too much trans fat can lead to unwanted weight gain and chronic inflammation. And, it can also increase your risk of diabetes, heart disease, and other health problems, too.
"Trans fats have been linked to a variety of health issues such as high cholesterol, weight gain, and an increased risk of developing heart disease," Novak warns. "Studies have also found that trans fats increase inflammation in the body which can lead to a host of other health problems." Trans fats can also slow your metabolism. Instead of processed foods high in trans fats, Novak advises eating foods made with whole grains and healthy oils.
"Whole grains such as quinoa or oats are packed with vitamins, minerals, fiber, protein, and antioxidants which can help to support weight loss efforts by keeping you fuller for longer periods of time," Novak says. Whole grains have been linked to reduced risk of certain cancers and improved heart health, she adds.
5. High Fructose Corn Syrup
High fructose corn syrup (HFCS), a common sweetener found in many processed foods and sugary beverages, has been associated with detrimental effects on gut health and abdominal fat. Excessive consumption of HFCS can disrupt the balance of gut microbiota, favoring the growth of bacteria linked to inflammation and metabolic dysfunction while diminishing beneficial bacteria.
"Excessive consumption of HFCS has been associated with increased intestinal permeability, also known as leaky gut. A compromised gut lining can allow harmful substances to enter the bloodstream, triggering inflammation and potentially leading to fat accumulation in the abdominal region," Singh notes.
6. Artificial Sweeteners
Artificial sweeteners, often used as sugar substitutes in various low-calorie and diet products, have been associated with potential negative impacts on gut health and abdominal fat. Studies suggest that artificial sweeteners can disrupt the balance of gut microbiota, potentially promoting the growth of bacteria linked to metabolic disturbances and inflammation while reducing beneficial microbial diversity. This alteration in gut flora may contribute to insulin resistance and weight gain, including the accumulation of abdominal fat.
"Examples like aspartame, saccharin, and sucralose are commonly used in diet sodas, sugar-free products, and processed foods. Although they contain few to no calories, some studies suggest that artificial sweeteners can negatively affect gut bacteria composition and metabolism. Altered gut microbiota may contribute to weight gain and fat storage, including belly fat," Singh shares.
