Fat tissue is the same as adipose tissue. Adipose tissues are loose connective tissues in the body that contains of fat. Excessive amount of fat is harmful to the body. However, fat is still needed in protecting and providing energy to the body. So we need to make that fat is still included in our diet. Yes, BMI cannot determine if your weight comes from fat or muscle. Body Mass Index or BMI is the relationship of your body weight compared to your height. It is a way of knowing if a person's weight is considered healthy. Using a BMI chart, you get your height and your weight and it corresponds to A BMI. An ideal BMI, considered to be healthy is 18.5 to 24.9.