
Are you over 40, and want to reduce your body fat percentage? In order to lose fat without muscle, you need to combine a healthy diet with strength training and adequate protein intake, explains Tara Collingwood, MS, RDN, CSSD, LD/N, ACSM-CPT, a Board Certified Sports Dietitian and co-author of the Flat Belly Cookbook for Dummies. “These foods are nutrient-dense, high in protein or fiber, and help regulate blood sugar and satiety, all key to maintaining lean mass during fat loss,” she explains.
Eggs

The first food Collingwood recommends eating is eggs. “Rich in complete protein and leucine, an amino acid that stimulates muscle protein synthesis,” she says. “High satiety keeps you fuller longer, which can help reduce overall calorie intake.”
Skinless Chicken Breast (or Turkey Breast)

The next food? Skinless chicken breast or turkey breast. “Lean, high-quality animal protein with minimal fat,” she says. “Supplies the amino acids your body needs to maintain muscle during calorie restriction.”
Salmon

Salmon, “or other fatty fish like sardines or mackerel,” is also great for fat loss. “Packed with protein and omega-3 fatty acids that support fat metabolism and reduce inflammation,” Collingwood says. “Omega-3s may improve muscle retention during weight loss, especially in older adults.”
Leafy Greens

She also encourages eating leafy greens, “like spinach, kale, Swiss chard,” she says. “Very low in calories, high in fiber, and rich in magnesium, which is important for muscle function. Helps you feel full without adding excess calories.”
Lentils and Other Legumes

Make sure to load your plate with lentils and other legumes. “High in plant protein, fiber, and slow-digesting carbs,” she says. “Good for muscle repair and also keeps insulin stable to support fat burning.”
Greek Yogurt

Greek Yogurt (plain, non-fat or low-fat) are amazing sources or protein with little fat. “High in casein and whey protein, both excellent for muscle maintenance,” Collingwood says. “Supports gut health (with probiotics), helps control hunger, and can double as a high-protein snack.”
Berries

Berries, including blueberries, raspberries, and strawberries, are great for burning fat. “Low in calories, high in fiber and antioxidants, which may support metabolic health,” says Collingwood. “Satisfy sweet cravings without spiking blood sugar.”
Also, Do These Things

To preserve muscle while losing fat, Collingwood recommends also doing these things:
Protein target: ~1.4-1.8 grams per kg of body weight per day.
Strength training: 3–5x/week to maintain or build lean mass.
Avoid crash diets: Aim for a modest calorie deficit (~300–500 kcal/day) to spare muscle.