Final answer:
Diets promote the loss of adipose tissue, also known as fat tissue.
Step-by-step explanation:
When it comes to diets, the tissue that is primarily lost is adipose tissue, also known as fat tissue. Diets that promote weight loss typically aim to reduce overall body fat by creating a calorie deficit, where the body burns more calories than it consumes. As a result, the excess fat stored in adipose tissue is metabolized for energy, leading to weight loss.