Best Fats for Bulking: The Skinny Guy's Secret Weapon

Here's a number that changes everything: fat has 9 calories per gram. Protein and carbs? Only 4.

That means every gram of fat you eat delivers more than double the energy of any other macronutrient. For skinny guys who struggle to eat enough food, fat isn't just important — it's your single most efficient tool for hitting a calorie surplus.

Yet most hardgainers barely think about fat. They obsess over protein. They stress about carbs. And they completely ignore the one macro that could make bulking feel effortless.

Let's fix that.

Why Fat Matters More Than You Think

Fat isn't just calories. It plays a direct role in the hormonal processes that build muscle.

Testosterone production depends on dietary fat. Multiple studies have shown that men who drop below 20% of calories from fat see measurable decreases in testosterone levels. For a skinny guy trying to add size, low testosterone is the last thing you need.

Fat also helps you absorb fat-soluble vitamins — A, D, E, and K. Vitamin D alone is linked to muscle protein synthesis, bone density, and immune function. Without enough dietary fat, you're literally flushing these vitamins down the drain.

And then there's the practical side: fat makes food taste good. A dry chicken breast is a chore. That same chicken cooked in olive oil with some avocado on the side? Now it's a meal you actually want to eat.

How Much Fat Do You Need While Bulking?

The sweet spot for most bulking skinny guys is 25-35% of total calories from fat. Here's what that looks like in practice:

Another way to think about it: aim for roughly 0.4-0.55g per lb of bodyweight as a minimum baseline. So a 154 lb guy should be eating at least 56-84g of fat per day.

Don't Go Too Low

Dropping fat below 20% of calories is a mistake. You'll feel terrible — low energy, brain fog, tanked libido — and your hormones will take a hit. This isn't a cutting guide. You're bulking. Eat the fat.

Don't Go Too High Either

Going above 40% of calories from fat means you're probably not eating enough carbs, which are your primary fuel for intense training. Carbs drive performance in the gym. Fat fuels recovery and hormones outside of it. You need both.

If you want a deep dive on the carb side of the equation, check out our guide to the best carbs for bulking.

The 10 Best Fat Sources for Bulking

Not all fats are created equal. Here are the ones that give you the most bang for your buck — calorie density, nutrient quality, and ease of eating combined.

1. Peanut Butter (and Other Nut Butters)

The king of bulking fats. Two tablespoons of peanut butter pack 190 calories, 16g fat, and 7g protein. It goes with everything — shakes, oats, toast, rice cakes, or straight off the spoon at midnight.

Almond butter and cashew butter work just as well. The calorie differences between them are negligible.

If you're making high-calorie shakes for weight gain, a big scoop of peanut butter is the easiest way to push a shake past 700 calories.

2. Extra Virgin Olive Oil

One tablespoon: 119 calories, 14g fat. It's almost pure energy in liquid form.

Drizzle it on rice, pasta, salads, roasted vegetables — anything savory. You won't even taste it past a tablespoon, but your calorie count will notice.

Olive oil is rich in monounsaturated fats (MUFAs), which are associated with reduced inflammation and better cardiovascular health. When you're eating 3,000+ calories a day, keeping your heart healthy matters.

Easy hack: After plating your food, just pour a tablespoon of olive oil over the top. That's an instant 120 calories with zero extra chewing.

3. Avocados

Half an avocado gives you roughly 160 calories, 15g fat, and 6g fiber. The fiber keeps your digestion running smoothly, which matters a lot when you're eating a high volume of food.

Avocados are loaded with potassium (more than bananas, actually), which helps with muscle contractions and reducing cramps during training.

Mash it on toast, slice it into a burrito bowl, blend it into a shake for creaminess, or just eat it with a spoon and some salt.

4. Whole Eggs

Stop eating just egg whites. The yolk is where the magic happens.

One whole large egg has 72 calories, 5g fat, and 6g protein. The yolk contains nearly all of the egg's vitamins and minerals — including vitamin D, B12, choline, and selenium.

Research has also shown that whole eggs stimulate muscle protein synthesis more effectively than egg whites alone, even when protein content is matched. The fats and micronutrients in the yolk appear to enhance the anabolic response.

Eat 3-4 whole eggs per day without guilt. The cholesterol fear from the 90s has been thoroughly debunked. Dietary cholesterol has minimal impact on blood cholesterol for most people.

5. Salmon and Fatty Fish

6 oz of Atlantic salmon delivers roughly 350 calories, 22g fat, and 34g protein. It's one of the only foods that's simultaneously a great protein AND fat source.

The omega-3 fatty acids (EPA and DHA) in salmon are anti-inflammatory powerhouses. They reduce exercise-induced muscle soreness, support joint health, and may even enhance muscle protein synthesis.

Other great fatty fish options:

• Mackerel — highest omega-3 content of any common fish
• Sardines — cheap, shelf-stable, surprisingly macro-friendly
• Trout — milder taste, similar nutritional profile to salmon

Aim for 2-3 servings of fatty fish per week. If you hate fish, a quality fish oil supplement (2-3g EPA+DHA daily) is a reasonable substitute — but real food is always better.

6. Mixed Nuts

A small 1.5 oz handful of mixed nuts packs around 230 calories and 20g of fat. Nuts are the ultimate no-prep snack for skinny guys who need to eat more throughout the day.

Best nuts for bulking:

Macadamias and pecans win on calorie density, but honestly — eat whichever ones you'll actually eat consistently. Check out our full list of high-calorie bulking snacks for more ideas.

7. Cheese

1 oz of cheddar cheese: 113 calories, 9g fat, 7g protein. It adds flavor, calories, and protein to almost any meal.

Sprinkle it on eggs, melt it on burgers, add it to pasta, or just eat it as a snack with crackers. Hard cheeses like parmesan, cheddar, and gouda are the most calorie-dense.

8. Dark Chocolate

This one surprises people. 1.5 oz of 70%+ dark chocolate has about 230 calories and 14g fat, plus antioxidants, magnesium, and iron.

It's a legitimate bulking food. Keep a bar in your desk and have a few squares as an afternoon snack. You're not cheating — you're hitting your macros.

9. Coconut (Oil, Milk, Flakes)

Coconut products are fat-dense and versatile:

• Coconut oil (1 tbsp): 121 calories, 13g fat
• Full-fat coconut milk (½ cup): 223 calories, 24g fat
• Dried coconut flakes (1 oz): 185 calories, 18g fat

Coconut milk is incredible in shakes and curries. The medium-chain triglycerides (MCTs) in coconut are quickly absorbed and used for energy, making them less likely to be stored as body fat.

10. Seeds (Chia, Flax, Hemp, Pumpkin)

Seeds are underrated fat sources with bonus micronutrients:

Toss them into oatmeal, yogurt bowls, smoothies, or salads. You won't taste them, but they add significant calories and nutrients.

Monounsaturated vs. Polyunsaturated vs. Saturated: Does It Matter?

Yes, but don't overthink it. Here's the simple breakdown:

Monounsaturated Fats (MUFAs)

Sources: Olive oil, avocados, almonds, cashews, peanuts

These should make up the bulk of your fat intake. They support heart health, reduce inflammation, and are linked to better insulin sensitivity — all good things when you're eating in a calorie surplus.

Polyunsaturated Fats (PUFAs)

Sources: Fatty fish, walnuts, flaxseed, chia seeds, sunflower seeds

These include the essential omega-3 and omega-6 fatty acids your body can't produce on its own. Omega-3s (from fish, flax, chia) are anti-inflammatory and support recovery. Most people get plenty of omega-6 from cooking oils and processed foods — it's the omega-3s you need to prioritize.

Saturated Fat

Sources: Whole eggs, cheese, butter, coconut oil, red meat

Saturated fat has been demonized for decades, but recent research shows it's not the villain it was made out to be. In moderate amounts, saturated fat supports testosterone production and is a normal part of a healthy diet.

A good rule of thumb: keep saturated fat under 10% of total calories. For a 3,000-calorie bulk, that's about 33g or less. This gives you room for eggs, cheese, and the occasional burger without going overboard.

5 Easy Ways to Add 500+ Calories of Fat Per Day

If you're currently under-eating fat, these small additions can transform your calorie intake without requiring you to eat more food volume.

1. Morning shake upgrade: Add 2 tbsp peanut butter + 1 tbsp coconut oil to your breakfast shake. That's +310 calories.

2. Cook with olive oil: Use 2 tablespoons of olive oil when cooking lunch and dinner instead of cooking spray. That's +240 calories.

3. Handful of nuts: Keep a bag of mixed nuts at your desk. One 2 oz handful mid-afternoon adds +290 calories.

4. Avocado with lunch: Half an avocado sliced onto whatever you're already eating adds +160 calories.

5. Night-time snack: 1.5 oz of dark chocolate + a tablespoon of almond butter = +340 calories.

Any combination of 2-3 of these gets you past 500 extra calories per day. That alone is enough to move the scale for most skinny guys.

Sample High-Fat Bulking Day

Here's what a full day of eating might look like when you prioritize fat strategically alongside your protein and carb needs. This plan targets roughly 3,200 calories with 110g of fat — perfect for a 154 lb guy on a lean bulk.

Notice how the fat is spread throughout the day, not crammed into one meal. This keeps energy levels stable and helps with digestion.

For more structured meal plans, check out our 3,000-calorie meal plan for muscle gain or our guide to meal prep for muscle gain.

Common Mistakes With Fat on a Bulk

1. Going Too Low-Fat Because "Fat Makes You Fat"

This myth refuses to die. Excess calories make you gain fat, not dietary fat specifically. In fact, going too low-fat on a bulk usually backfires — you end up with low energy, bad moods, and a terrible hormonal profile. Fat is your friend during a bulk.

2. Only Getting Fat From Junk Food

There's a difference between getting your fats from nuts, avocados, and olive oil versus getting them from deep-fried everything and processed snacks. Both hit your calorie target, but the quality matters for recovery, inflammation, and long-term health.

This is closely related to the dirty bulk vs. clean bulk debate — and the answer is usually somewhere in the middle.

3. Ignoring Omega-3s

Most guys eat plenty of omega-6 fats (from vegetable oils, processed foods) but almost no omega-3s. This imbalance promotes chronic inflammation, which slows recovery and can even impair muscle growth. Eat fatty fish twice a week or supplement with fish oil.

4. Not Counting Fat Calories

Fat is easy to over- or under-eat because it's so calorie-dense. A tablespoon of olive oil that you eyeballed could be 120 or 240 calories depending on how generous your pour was. If you're tracking your macros, measure your oils and nut butters for the first few weeks until you can eyeball accurately.

5. Forgetting Fat When Meal Prepping

You prep your chicken and rice for the week, but forget to add a fat source. Now your meals are dry, bland, and lower calorie than planned. When you meal prep for muscle gain, always include a fat element — a container of mixed nuts, pre-portioned nut butter cups, or a bottle of olive oil at your desk.

How Fat Fits Into Your Overall Macro Split

Here's a practical framework for setting up your bulking macros:

1. Protein first: Set protein at 0.7-1.0g per lb of bodyweight
2. Fat second: Set fat at 25-35% of total calories
3. Carbs last: Fill remaining calories with carbs

For a 165 lb guy eating 3,200 calories:

• Protein: 150g (600 cal)
• Fat: 100g (900 cal, ~28% of total)
• Carbs: 425g (1,700 cal)

If you need help figuring out your protein target specifically, our guide on how much protein you need to build muscle breaks it down in detail.

Why FuelTheGains Makes This Easier

Figuring out the right fat intake — and balancing it with protein and carbs — is one of the trickiest parts of bulking. It's not just about knowing what to eat; it's about building a daily plan that hits your targets consistently.

That's exactly what FuelTheGains does. You enter your stats, and it generates a personalized bulking meal plan with the right macro split already calculated — including fat targets. No guesswork, no spreadsheets, no staring at MyFitnessPal wondering why your numbers don't add up.

If the math side of nutrition isn't your thing, let the tool handle it so you can focus on actually eating and training.

The Bottom Line

Fat is the most calorie-efficient macro you can eat. For skinny guys who struggle to reach a surplus, prioritizing healthy fats is the simplest way to add hundreds of calories without stuffing yourself.

Focus on nut butters, olive oil, avocados, eggs, fatty fish, and nuts. Keep saturated fat reasonable. Don't skip omega-3s. And spread your fat intake across the day.

Start with one small change — add a tablespoon of olive oil to your next meal — and build from there. Your scale will thank you.