1. Vegetable oils
Vegetable oils, such as soybean oil, corn oil, and sunflower oil, are often high in omega-6 fatty acids, which, when consumed in excess, can contribute to inflammation in the body. While omega-6 fatty acids are essential for health, the Western diet typically contains an imbalance of omega-6 to omega-3 fatty acids, favoring omega-6, which can promote inflammation when not balanced properly.
"Vegetable oils can be inflammatory due to an imbalance between omega-6 and omega-3 fatty acids," nutritionist Lisa Richards explains. "While both types are essential for health, the typical Western diet contains an excessive amount of omega-6 fatty acids, primarily found in vegetable oils."
2. Artificial sweeteners
Research suggests that artificial sweeteners can disrupt the balance of gut bacteria, leading to inflammation in the gastrointestinal tract. Additionally, artificial sweeteners may promote sugar cravings and dependence on sweet-tasting foods, potentially increasing consumption of calorie-dense options.
Health expert Joanna Wen says, "While they may seem like a healthy alternative to sugar, artificial sweeteners can actually lead to inflammation in the body, which can contribute to weight gain and other health issues."
3. Margarine
Margarine, a common butter substitute made from vegetable oils, can be inflammatory due to its high content of omega-6 fatty acids, particularly when it contains partially hydrogenated oils or trans fats. Additionally, margarine often undergoes a hydrogenation process to solidify the oils, which can create trans fats, known to be highly inflammatory.
Nutritionist Nataly Komova discourages people from eating it because it is "the unhealthiest of all spreads and butters. It mostly carries large amounts of trans-fats and pro-inflammatory omega-6 fats—the worst fats that increase LDL, leading to a risk of heart diseases. Additionally, higher trans-fats potentially cause insulin resistance, which lowers metabolism."
4. Sugar
This one may be no surprise, but sugar consumption is closely linked to weight gain due to its high calorie content and lack of essential nutrients. Sugary foods and beverages are often calorie-dense but nutrient-poor, leading to excess calorie intake without providing satiety or essential vitamins and minerals.
Functional nutritionist Amy Lippert says, "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."
And that's not all, she further notes that "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."
5. Processed Meats
Processed meats often contain high levels of unhealthy fats, such as saturated fats and trans fats, which can contribute to inflammation in the body when consumed frequently. Some of them contain additives, such as preservatives and flavor enhancers, which can further contribute to inflammation and metabolic dysfunction.
"Sausages, bacon, hot dogs, and deli meats that have been cured, smoked, or salted often contain high levels of saturated fats, as well as additives such as nitrates and nitrites, which can contribute to inflammation. Processed meats are also high in calories and salt, which can lead to weight gain and increased blood pressure," Dr. Kezia Joy, MD, says. She also adds that these types of meats are "high in saturated fats which can lead to obesity and systemic inflammation."
6. Red Meats
Red meats are high in saturated fat content and can elicit inflammatory responses in the body when consumed excessively, potentially leading to conditions like insulin resistance and cardiovascular issues. Moreover, red meats are often calorie-dense, and their frequent consumption without balancing a healthy diet or physical activity can contribute to weight gain.
Joy states that "fatty cuts of red meat (like ribeye or T-bone steaks) and ground beef with high fat content can promote inflammation and weight gain when consumed in excess. They are high in saturated fats, which can raise bad cholesterol levels (LDL) and contribute to the development of heart disease. Some research also suggests that a compound called neu5gc, found in red meat, may cause inflammation."
7. Sugary Condiments
Sugary condiments like ketchup, barbecue sauce, and sweet chili sauce are commonly overlooked sources of added sugars in diets. Despite their small serving sizes, these condiments can pack a significant amount of sugar, contributing to excess calorie intake and promoting weight gain when consumed regularly. Their high sugar content in these condiments can lead to spikes in blood sugar levels, triggering inflammatory responses in the body.
Mary Sabat MS, RDN, LD says, "These condiments often contain high fructose corn syrup and added sugars, which can lead to inflammation when consumed in excess. They also add empty calories to meals, potentially contributing to weight gain."