What Should I Eat When I Want to Get Lean?

To build muscle and burn fat, you shouldn’t starve your way to your desired shape. As a registered dietitian and expert in weight management, I’ll help you plan meals that fill your plate with muscle-building, fat-fighting foods.

Losing Fat and Sparing Muscle

When a client’s goal is weight loss, I try to quell the notion that the number on the scale is the only measure of success. Body composition matters more. Our bodies are made up of water, muscle (lean mass), and fat mass. Losing fat and making muscle results in a lean, toned look.

Your body has to be in a calorie deficit in order to use (and lose) fat stores for fuel, but there’s a fine balance. Calories are needed to keep our hearts pumping, lungs working, and brains functioning. We also use energy to digest and metabolize food, and fuel physical activity. 

Exercise provides the most variable number of calories burned.

When you exercise, your body relies on carbs first. Carbs may come from toast, yogurt, or fruit you ate at breakfast, or glycogen, the carbohydrates stored in your liver and muscles that are used between meals for energy. 

Without adequate calories or carbs, your body may use muscle for energy because amino acids can be used to make glucose. But that’s not sustainable. Fat is used for calories to spare muscle. Through a series of metabolic processes, fat is broken down into water and carbon dioxide and expelled through respiration (breath), perspiration (sweat), and urination (urine).

Reducing calorie intake alone may be best to retain muscle. One study comparing a low-carb diet plus exercise to a calorie-restricted diet plus exercise found greater fat losses in both men and women, but muscle mass was also lost in these groups who were overweight or obese. 

I advise a 500- to 700-calorie deficit per day to lose roughly one pound of weight per week. You can calculate your baseline calorie needs with the NIH’s body weight planner tool.

What Should I Eat to Get Lean?

Start with lean protein. Lean beef like eye of the round or sirloin, eggs, low-fat dairy products, fish, poultry, lean pork, and seafood provide protein to build muscle, as do beans, lentils, and soy-based products. Protein powder or shakes can also be used to increase protein in your diet.

Diets high in animal protein are popular, but some research suggests dairy products (whey protein) and plant-based protein from beans and soy products may impact weight loss more. 

According to scientists, branched-chain amino acids, including methionine, tryptophan, and the metabolite glutamate, may enhance the maintenance of lean body mass, and promote satiety. 

While the RDA (recommended dietary allowance) for protein is .36 grams per pound (.8 grams per kilogram), you need more to support muscle growth. Research suggests 1.2–1.59 grams of protein per kilogram of body weight each day in adults older than 65. In those younger than 65, 1.6 grams per kilogram is advised — twice the RDA — to prevent muscle loss.

When compared to calorically-similar diets, a systematic review found that a higher-protein diet (>25% of calories) resulted in more fat loss and lean muscle retention in older adults compared with a lower-protein diet (<25% of calories). 

Keep in mind that eating more protein without resistance training won’t lead to more muscle. Research evaluating protein supplementation and/or a high-protein diet with or without resistance exercise (RE) found that higher-protein intake resulted in more lean body mass but only when combined with RE.

Have you heard that a high-fat, low-carb diet might help? When compared to a well-balanced diet with moderate calorie restriction (700 calories less per day) and exercise, the high-fat, low-carb diet wasn’t better for reducing body fat and overall weight in overweight and obese women. 

Don’t ditch grains. A study comparing whole grains (rolled oats, whole-grain pasta, brown rice) to refined grains (white bread, cookies, pop tarts) in weight management found that whole grains helped reduce body weight and markers of inflammation. Whole grains also contain fiber, which fills you up.

Include leafy green vegetables and fresh or frozen fruit. Your muscles work hard. Potassium is needed for muscle contraction and for managing blood pressure and heart function. 

Vitamin C from produce helps reduce inflammation and the production of free radicals after exercise. Fruits and vegetables are low-calorie, nutrient-dense foods that also lower the risk of several diseases.

What Should Men Eat to Get Lean?

I know it’s not fair, but men can afford to eat more than women. They have higher nutritional needs due to larger overall body mass (weight) and lean muscle mass. What should men eat when they want to get leaner? Is low carb better than calorie restriction for fat loss?

In trained, middle-aged men, a low-carb, ketogenic diet compared to a non-ketogenic diet with similar calorie levels was found to have the same impact on body composition, muscle strength, and hormonal and lipid levels. 

My client Doug is a 42-year-old male trying to lose his “spare tire” and build more muscle. Doug is 5’10” and weighs 210 pounds. He does three days of 45-minute bootcamp-style workouts with his friends and two days of lifting at his local gym. Doug complains of getting light-headed on his bootcamp workout days.

I calculated Doug’s calorie needs at 2,500 per day for weight loss, considering his age, sex, height, weight, and activity level. His protein needs are 90 to 120 grams per day in order to support fat loss and muscle growth.

Since Doug complained of being light-headed before workouts, I suggested a 150-calorie protein shake and 12–16 ounces of water before his workout. Fortunately, eating protein or fasting before working out still results in fat loss in trained individuals. 

Eating carbs before a workout doesn’t promote fat loss. After exercise, high-carb foods should be eaten with protein to replete glycogen stores.

Doug’s meal plan includes lean protein, lots of vegetables and fruit, moderate amounts of whole grains, low-fat dairy products, and limited amounts of fats. With this eating plan, Doug lost 20 pounds in four months but stayed strong.

Meal Plan for Middle-Aged Male

• Pre-workout: 150-calorie protein shake (20 grams protein)

Breakfast 

• 2 scrambled eggs (14 grams protein)

• 2 slices whole grain toast (6 grams protein)

• 8 oz. skim or 1% milk (8 grams protein)

• 1 banana

AM Snack

• ½ cup low-fat cottage cheese (12 grams)

• 1 cup cantaloupe

Lunch 

• 4 cups romaine lettuce (2 grams protein)

• 4 oz. grilled chicken (35 grams protein)

• ½ cup black beans (7 grams protein)

• ½ cup brown rice (3 grams protein)

• ¼ cup shredded cheddar cheese (6 grams protein)

• 2 Tbsp. ranch dressing

• 1 cup blueberries

Dinner

• 2 cups steamed broccoli (5 grams protein)

• 1 baked potato (4.3 grams protein)

• 4 oz. grilled salmon (24 grams protein)

• 2 tsp. whipped butter

• ½ cup red grapes

Optional snack

• 5 oz. Greek yogurt (15 grams protein)

• 1 cup strawberries 

Total daily protein amount: 161 grams

Women’s Diet to Get Lean

I advise women to eat at least 1,500 calories per day if they’re working out while trying to lose fat and gain muscle. Below this level, they may not have enough energy to exercise and could risk losing muscle mass in the process.

In 101 post-menopausal women, one study found that those in a very low-calorie diet group lost more weight (14.52 pounds versus 7 pounds) and muscle mass (2.64 pounds) compared to those on a moderate calorie reduction. 

Intermittent fasting combined with HIIT training may be beneficial for fat loss in active women. In a small study, a 14:10 window was used (14 hours fasting, 10 hours eating). Macronutrients were divided as protein: 1.8–2 g/kg of body mass, carbohydrate 5–8 g/kg of body mass, and fat comprised 1–1.2 g/kg of body mass. Performance was not affected by IF. More studies are needed to evaluate long-term effects.

Protein intake is important for women, too. Whey protein isolate has been shown to favor muscle growth in young, healthy adults doing resistance training, though it may not change fat mass. Timing of whey protein intake may make a difference. One study showed that 35 grams of whey protein taken after workouts improved lean body mass in older women. 

Protein should be distributed evenly throughout the day and not “saved” for just dinner. A study in healthy men and women found better muscle protein synthesis when protein was consumed at breakfast, lunch, and dinner. Each meal contained roughly 30 grams of protein.

Meal Plan for Healthy Active Woman

My client Jill dubs herself a “gym rat.” She’s a 38-year-old who does five days of cardio (elliptical plus treadmill for 30 minutes each) and two days of strength training with a personal trainer. She’s lost 20 pounds, but she’s hit a plateau and feels weak. Her diet history revealed she was eating 1,400 calories per day. Jill is 5’7” and weighs 180 pounds. She works out after work.

Jill’s calorie and protein needs were estimated at 1,900 calories and 60–75 grams of protein per day (1.0–1.2 grams per kg of ideal weight). After eight weeks of diet change, Jill reduced her body fat by three percent.

Breakfast

• ½ cup rolled oats with ½ scoop protein powder (15 grams protein)

• 1 cup skim or 1% milk (8 grams protein)

• 1 banana

AM snack

• Hard-boiled egg (7 grams protein)

• 1 apple

Lunch

• 2 slices whole grain bread (6 grams protein)

• 3 slices lean turkey (18 grams protein)

• 1 slice cheddar cheese (7 grams protein)

• 2 cups raw veggies

• 2 Tbsp. hummus (3 grams protein)

• 2 clementines

Post-workout

• Whey protein shake (20 grams protein)

Dinner

• 3 oz. baked cod (20 grams protein)

• ½ cup mashed sweet potatoes (2 grams protein)

• 8 asparagus spears (2 grams protein)

• 1 tsp. whipped butter

• 1 cup cantaloupe

Bottom Line

If your goal is to lose body fat and maintain muscle, focus on moderate calorie reduction and increasing protein in your diet to roughly 1.2 grams or more per kilogram of body weight. 

Cut out foods that are prone to pack on belly fat like sweetened beverages, alcohol, and other empty calories from chips, candy, and snacks. Choose lean protein and limit fried food, heavy cream or cheese sauce, and fast food. Drink plenty of water for hydration before, during, and after exercise, and be sure to get enough sleep.

For more tips on healthy eating, an expert can help. Reach out to a registered dietitian, or check out the Kickoff app’s nutrition features and learn how you can work with a certified expert to help you reach your health and nutrition goals.