Research says that sugar, not fat, is the no-go ingredient when it comes to a healthy diet. It upsets your blood sugar and insulin levels, encourages fat storage, and contributes to the rise in obesity, type 2 diabetes, and other health issues. If you are tempted to use a sugar substitute, you need to be careful as studies have suggested that artificial sweeteners could contribute to both weight gain and insulin sensitivity more than sugar. It is best to consult an expert before making any changes to your diet.