A diet that provides 1,500 calories a day is likely to produce weight loss. If your goal is to build muscle and lose fat while lowering your total daily energy intake to 1,500 calories, you must make appropriate adjustments to your diet to ensure that the weight you lose is fat and not muscle. Please consult your physician before altering your diet.
Protein, carbohydrates and fat all provide energy in your diet and are collectively known as macronutrients. When attempting to simultaneously lose fat and build muscle, the macronutrient profile of your diet must be modified from that of your maintenance diet. Increase your protein intake to around 40 percent of total energy, which, at 1,500 calories a day, equates to a daily protein intake of 150 grams. Consume the remainder of your daily energy allowance as 40 percent carbohydrate and 20 percent fat.
Meet your protein requirement from primarily animal foods, such as turkey and chicken breast. These foods contain high quality protein and are low in fat. Eat carbohydrates that have a low glycemic index, meaning that they release sugar slowly into the bloodstream. Choose whole-grain versions of bread, pasta and rice and increase your intake of vegetables such as sweet potato, mushrooms, zucchini and broccoli. Aim to meet your fat requirements from vegetable, nut and seed oils, in addition to the intrinsic fat contained in the protein and carbohydrate foods you consume.
Leaving too long a gap between meals will cause your body to break down muscle tissue as well as fat for energy. Divide your calorie allowance over five or six smaller meals and eat more frequently over the course of a day. According to bodybuilding author Robert Kennedy, this pattern of eating ensures that your body has a constant supply of protein, and can help offset the muscle degradation often associated with a calorie deficit.
When you decrease your calories to an intake as low as 1,500 per day, your intake of vitamins and minerals will also decrease. Take a daily multivitamin and mineral supplement to safeguard against deficiencies until you return to your maintenance intake of energy. You can also use whey protein shakes to meet your increased requirement for protein. Supplemental whey alone is not adequate to meet your need for vitamins and minerals, but is a convenient source of high quality protein and contains very little fat and carbohydrate. Consume around 20 grams of whey before and after each workout. Check with your physician before taking any supplements.