Turning 40 is a milestone  one that often comes with changes in metabolism, hormones, muscle mass, and overall energy levels. What worked for you in your 20s or 30s, skipping meals, loading up on red meat, or relying on late-night snacks, may now leave you with weight gain, fatigue, and other health concerns. Fortunately, your diet can be your strongest ally in staying lean, energized, and hormonally balanced.

At Men’s Clinic South Africa, we help men make smarter lifestyle choices. In this post, we’ll break down the best diet tips for men over 40, supported by science and practical enough to apply right away.

Prioritize Protein with Every Meal

As men age, they naturally begin to lose muscle mass (a process called sarcopenia), which can slow metabolism and increase fat gain. A high-protein diet supports muscle maintenance, hormone production, and satiety.

Best Sources:

• Lean meats (chicken, turkey)

• Eggs

• Greek yogurt

• Legumes

• Fish (especially omega-3-rich like salmon)

• Plant-based options like tempeh or tofu

Tip: Aim for at least 25–30 grams of protein per meal.

Reduce Refined Carbs and Added Sugars

Carbohydrates aren’t the enemy, but refined carbs (like white bread, pasta, and sugary snacks) spike insulin, encourage fat storage, and increase the risk of Type 2 diabetes, a growing concern for men over 40.

Instead, focus on:

• Whole grains (quinoa, oats, brown rice)

• Starchy vegetables (sweet potatoes, carrots)

• Fruits in moderation

• Legumes and fiber-rich foods

Pro Tip: Read nutrition labels. Many “healthy” foods are loaded with added sugars.

Support Testosterone Naturally

Low testosterone can contribute to fatigue, weight gain (especially around the midsection), and reduced libido. Diet plays a role in optimizing hormone levels.

Key nutrients for testosterone:

• Zinc (found in oysters, pumpkin seeds, beef)

• Vitamin D (sunlight, egg yolks, fatty fish)

• Magnesium (spinach, almonds, dark chocolate)

• Healthy fats (avocados, olive oil, nuts)

Avoid: Excess alcohol, soy-based highly processed foods, and BPA-lined canned goods, all of which may affect hormone balance.

Embrace Healthy Fats

Fat is essential for hormone production and brain health, especially for aging men. But not all fats are created equal.

Eat more:

• Omega-3s (salmon, flaxseeds, walnuts)

• Monounsaturated fats (olive oil, avocados)

• Pasture-raised eggs

Avoid:

• Trans fats (found in processed snacks and baked goods)

• Excess omega-6 fats from cheap vegetable oils

 

Drink More Water (And Less Alcohol)

Hydration is often overlooked. Dehydration affects energy, digestion, and even mood. Aim for at least 8–10 cups of water per day.

As for alcohol, moderation is key. Regular alcohol intake:

• Increases estrogen levels

• Lowers testosterone

• Contributes to weight gain

• Impacts sleep quality

Swap sugary mixers and beers for red wine (in moderation) or low-carb spirits if you choose to drink.

Understand Your Changing Metabolism

As men age, their basal metabolic rate (BMR), the number of calories burned at rest—declines due to a natural loss of muscle mass and hormonal shifts.

What this means for your diet:

• You may require fewer daily calories than you did in your 20s or 30s.

• The focus should shift from just calorie restriction to nutrient quality and muscle preservation.

Tip: Aim for nutrient-dense, whole foods and combine your diet with resistance training to counteract muscle loss.

Manage Belly Fat and Insulin Sensitivity

Visceral fat (belly fat) increases your risk of heart disease, type 2 diabetes, and low testosterone.

Key tips:

• Cut back on refined carbs and sugars: soda, white bread, pastries

• Emphasize complex carbohydrates: sweet potatoes, oats, brown rice, legumes

• Incorporate healthy fats: avocados, olive oil, nuts, fatty fish (like salmon)

Bonus: These foods support healthy cholesterol levels and reduce inflammation.

Boost Testosterone Through Nutrition

Testosterone production can decline about 1% per year after 30. Some nutrients play a key role in supporting hormonal balance.

Top testosterone-friendly foods:

• Zinc-rich foods: oysters, pumpkin seeds, beef, spinach

• Vitamin D: fatty fish, eggs, fortified dairy, sun exposure (or a supplement if deficient)

• Magnesium: leafy greens, almonds, dark chocolate

• Cruciferous vegetables: broccoli, Brussels sprouts, cauliflower (support estrogen balance)

Avoid:

• Excessive alcohol

• Ultra-processed foods and trans fats

• Low-fat diets (some dietary fat is essential for hormone production)

Eating right after 40 isn’t about restriction, it’s about smarter, more intentional choices that work with your changing body. By prioritizing lean protein, whole foods, fiber, healthy fats, and key micronutrients, you can build a strong foundation for the decades ahead.

Remember: small, consistent changes beat crash diets every time. Whether you want to lose weight, build muscle, support testosterone, or boost energy , your plate plays a powerful role in how you age.

Start with one or two of these tips this week. Your future self will thank you.