Cooking with healthy fats is something that has been explained over and over again in recent months. Healthy cooking oils are a great way to acquire those healthy fats in your diet. Think olive oil, coconut oil and others but experts are saying there is one common oil that actually may be leading to weight gain, soybean oil. For many years, this oil was considered a healthier alternative compared to oils that contain a lot of saturated fat. But now a new study concludes it may lead to more weight gain that fructose.