ISSA Certified Personal Trainer/Nutrition Guidance



Carbohydrates provide the energy you need to strength train and build muscle; protein is the building block of new, stronger muscle tissue; but, what about fats? Fat has been misunderstood for a long time, especially during the low-fat food craze during the 1980s and 1990s. 

We know better now. Fats are not only essential in the diet, but they can actually help you build more lean muscle mass. Learn how fats work to complement strength training and support your muscle gains. 

Why You Need Good Fats for Muscle Building

Most people looking to build muscle also want to shed some fat. They want to change their body composition to be leaner, with less fat and more muscle. It may seem counterintuitive then, to include a significant amount of fat in the diet. Here are a few reasons you need fat if you’re working on building muscle.

Workouts Are Fueled by Fat, Promoting Muscle Growth

A short workout will use carbohydrates for energy, but as you push through and do a longer session, your body runs out of readily available carbs. It turns to fats. If you don’t have enough body fat, you’ll simply run out of steam. And if you can’t push your body through the workout, you will never grow that muscle mass. 

Good Fats for Muscle Building Promote Good Cholesterol

There is an important muscle-building chain reaction here that begins with healthy fats. The so-called “good” fats in your diet—monounsaturated and polyunsaturated fats—increase levels of HDL, the good cholesterol. HDL leads to increased production of growth hormone, which in turn triggers more amino acids. These building blocks of protein are essential for building muscle tissue. 

Fat Absorbs and Stores Vitamins and Minerals 

Fat-soluble vitamins and minerals build up in fat tissue in the body. If your body fat is too low, you won’t be able to hold on to these important nutrients. By storing the right micronutrients, your body is able to perform optimally. Without them, you can’t workout effectively to build muscle. 

Fats Are Calorie-Dense and Keep You Full

A gram of fat is worth 9 calories of energy. This is about twice as much as the energy in proteins and carbs. Fatty foods are dense in calories, which means they leave you feeling satisfied and full. You’re less likely to binge on unhealthy foods if you have the right proportion of healthy fats in your diet. The healthier and more controlled your diet, the easier it is to build muscle mass. 

What is a Good Fat? A Bad Fat? 

When the no-fat, low-fat diet trend took over American eating decades ago, it portrayed all fats as bad. We know better now. Certain fatty foods are healthy, necessary parts of a well-rounded diet. These are unsaturated fats, which come from plants. When eaten in the right amounts, they do several important things for overall health

  • Improve cholesterol ratios
  • Stabilize heart rhythm
  • Reduce inflammation
  • Reduce blood pressure
  • Reduce risk of cardiovascular disease

Unsaturated fats can be monounsaturated and polyunsaturated. Examples of monounsaturated fats include the following: 

  • Avocados
  • Olive oil
  • Peanut oil
  • Canola oil
  • Many nuts and seeds

You’ll find polyunsaturated fats in the following: 

  • Soybean oil
  • Flax seeds and oil
  • Sunflower oil
  • Corn oil
  • Walnuts
  • Fatty fish

A subcategory of polyunsaturated fats is the omega fatty acid group. Of the three, omega-3 fatty acids are most important to include in the diet. The body cannot make them, and many people don’t get enough in what they eat. 

Omega-3 fats do important things like improve heart and brain health, decrease liver fat, and reduce inflammation. You can find them in the following foods: 

  • Fatty fish
  • Walnuts
  • Flax seeds
  • Chia seeds
  • Canola oil
  • Soybean oil

The Best “Good” Fat Foods for Building Muscle

A healthy number to shoot for when deciding how much fat to include in your diet is between 20% and 30%. To build muscle, this should be balanced with the right amount of carbs and protein to fuel workouts and avoid losing muscle mass. 

It’s easy to lose muscle mass instead of fat mass if you ignore your diet while training. 

The portion of your calorie intake from fat should be heavy in monounsaturated and polyunsaturated fats and low or very low in saturated and trans fats. Some saturated fats are fine in the diet, but avoid trans fats as much as possible. 


You get a lot of bang for your calorie buck with eggs. Eggs are nutrient-dense and provide both protein and fat. The B vitamins in eggs help your body produce more energy to fuel workouts. The proteins, particularly the amino acid leucine, in eggs build muscle tissue. 

Although eggs, yolks especially, contain saturated fats and cholesterol, the overall nutrient picture is good. Eggs contain both saturated fats and unsaturated omega-3 fatty acids. Unless you have high cholesterol, eggs can be a healthy, muscle-building choice for any time of day. 


Fatty, cold-water fish like salmon are rich in omega-3 fatty acids. Wild-caught salmon has about 2.2 grams of omega-3 fats per three-ounce serving. Farmed salmon has just a little less. Of course, fish is also an excellent source of protein, so you get two things in one with salmon. 

According to the Environmental Defense Fund, wild Alaskan salmon is the most eco-friendly choice. Tuna is another fatty fish with nutritional benefits, but it is a worse choice for the environment. It is also more likely to contain mercury. 

Nuts and Seeds

You can’t go wrong choosing any type of nut or seed to add to your diet. Go for a variety to get a range of micronutrients along with your healthy fats. Walnuts, chia seeds, and flax seeds are particularly good for adding omega-3 fats to your diet. Just be sure to get ground flax. The whole seeds will just pass through your digestive tract. 

Peanuts are best for including both protein and healthy fats. If you like peanut butter, choose natural nut butters of all types. Be aware that nuts and seeds have a high calorie density. If you’re trying to lose fat and gain muscle, don’t overdo it. 


Most of the calories in an avocado come from fat, but they’re mostly healthy fats. And avocados don’t have as many calories as you think. One large avocado has 322 calories, 19.7 grams of monounsaturated fats, and 3.7 grams of polyunsaturated fats. An avocado also has four grams of protein and significant amounts of vitamins C, E, and K, and the B vitamins. 

Coconut Oil

Coconut is one of the few plant sources of significant amounts of saturated fat. For this reason, coconut oil has long been demonized as a bad fat. Coconut oil may actually have some health benefits, including for muscle building. 

Most of the fats in coconut oil are medium-chain triglycerides, as opposed to the long chains in animal-based fatty foods. These shorter chains break down more quickly, providing fast energy that can boost your effort in a tough workout. It’s also a satisfying, rich food that will keep you feeling fuller longer. 

Research is changing how we look at saturated fats. They may not be as bad as we long thought, but a diet high in saturated fat is still more closely linked with cardiovascular disease than a diet high in unsaturated fats. For this reason, use coconut oil sparingly. Instead of simply adding coconut oil to your diet, use it to replace other sources of saturated fat, such as meat. 

Learning to Find Balance

Building muscle can be a tricky balance. Unfortunately, it’s more complicated than simply getting in the gym a couple times a week to lift weights. To make lasting gains, you need to consider diet too.