Introduction

Loss of muscle mass puts a person at greater risk of chronic disease, leads to weakness, and a reduction in life quality. As we age, it is a major contributor to disease. A healthy, balanced diet that includes oily fish can help prevent muscle loss.¹ According to the National Health Service (NHS), people should eat at least two portions of fish per week, including one portion of oily fish.² 

Oily fish (such as trout, salmon, mackerel, and sardines) contain 5-20% fat, whereas white fish (such as cod, pangasius, haddock, and tilapia) typically contain only 1-2% fat.³ Oil-rich fish contain long-chain omega-3 and omega-6 fatty acids, which our body does not produce. They have a multitude of health benefits, such as preventing heart disease and improving mental health. In addition to these benefits, oil-rich fish such as trout can be useful for supporting your muscles due to their omega-3 content.²

In this article, you will find out what nutrients trout contains, how it can improve and maintain your muscle health, and how to incorporate trout into your dietary plan.

Nutritional benefits of trout

Trout is an oil-rich fish, which means that it is a good source of fatty acids, which play many vital  functions in our body. Fatty acids are the building blocks of lipids (fats). There are three main types of fatty acids (fats): 

• Saturated
• Monounsaturated
• Polyunsaturated fatty acids (PUFAs)

Omega-3 fatty acids are PUFAs commonly found in marine oily fish. The two most studied and abundant omega-3 PUFAs, eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), are contained in trout.^4,5  Whilst there are several other types of omega-3 fatty acids, EPA and DHA are the most abundant in oily fish. The other main type - alpha-linoleic acid (ALA) - is found in plant foods such as walnuts. Omega-3 PUFAs are considered essential, as our body cannot produce them. Therefore, we must obtain them from our diet.

Trout is also rich in vitamins and minerals. 100 grams of baked rainbow trout (flesh only) contain:³

Despite its richness in healthy nutrients, trout contains relatively few calories compared to other types of fish and seafood. Raw rainbow trout (flesh only, 100 grams) contains 127 kcal, the same amount of mackerel – 233 kcal, salmon (cold smoked) – 184 kcal. The main reason for these differences is that trout contains less fat than salmon and mackerel. However, this is not to say that you should avoid salmon and mackerel.⁴

Muscle support with trout

Muscle anabolism

There is growing evidence that omega-3 PUFAs, especially EPA, improve protein synthesis (anabolism) and reduce protein breakdown (catabolism) in skeletal muscle. The balance between these two processes is essential for muscle growth and the maintenance of muscle mass. Some studies also indicate that omega-3 PUFAs may improve muscle function in combination with physical exercises, especially in older adults.

Omega-3 PUFAs intake may reduce the loss of muscle mass during periods of inactivity due to illness or injury. They may also enhance the body's response to protein intake, promoting muscle growth. These positive effects of omega-3 PUFAs on muscle mass and muscle function may be useful for preventing muscle wasting, such as sarcopenia.¹ 

Muscle metabolic flexibility and insulin resistance

Skeletal muscles can switch between using fats and glucose as fuel. This ability, known as metabolic flexibility, is often reduced in people with obesity and type 2 diabetes. Omega-3 PUFAs can enhance the muscles’ ability to use different energy sources, although results are controversial across studies. 

Some studies suggest omega-3 PUFAs can promote the incorporation of fatty acids in complex lipids within the muscle, thus reducing harmful lipid accumulation that can interfere with insulin signalling. 

Studies indicate that omega-3 PUFAs supplementation can increase fat oxidation and decrease glucose utilisation in healthy people, suggesting a shift towards using fat as a primary energy source during physical activities like exercise.¹

Inflammation

Besides their direct effects on metabolism, omega-3 PUFAs have significant anti-inflammatory effects, which could indirectly improve insulin sensitivity. In contrast, omega-6 PUFAs, especially arachidonic acid, tend to promote inflammation. Omega-6 PUFAs are still essential fatty acids. However, it is believed that too much omega-6 is the issue. This is known as the omega-3 to omega-6 ratio. Too much omega-6 PUFAs and insufficient omega-3s skew the ratio. This is typically seen in Western diets, hence promoting inflammation.

While some inflammation is necessary for muscle adaptation, excessive or chronic inflammation can contribute to health issues like insulin resistance and obesity. Omega 3-PUFAs (EPA and DHA) can change how inflammatory mediators like prostaglandins and leukotrienes are produced. They reduce the production of eicosanoids - substances causing inflammation.

In addition, omega-3 fatty acids may affect various aspects of immune function. They can enhance the activity of cells like lymphocytes and natural killer cells, which help regulate inflammation.¹

Cell membrane effects

All cells in our body are surrounded by a lipid membrane. Omega-3 PUFAs can significantly change the composition of cell membranes, even in small subcellular structures like mitochondria. By incorporating into cell membranes, omega-3 PUFAs can enhance the fluidity of these membranes. This change in fluidity can potentially improve functions like the glucose intake into cells.

However, most studies on the impact of omega-3 PUFAs on membrane composition and function have been conducted in immune cells or other cell lines, not specifically in human skeletal muscle cells. More research is needed to understand how these effects translate to skeletal muscle and whether they differ among various muscle fibre types.¹

Trout as a part of a balanced diet

Trout should be incorporated as a part of a healthy and balanced diet. Trout can be a component of salads, sandwiches, and main dishes. It can be easily combined with vegetables, fruits, grains, and olive oil, which enhances its health benefits.⁶ By experimenting with flavour combinations and new recipes, getting your 1-2 weekly portions of oily fish as per NHS recommendations will be easy. Make sure that the trout has been stored and prepared appropriately.² 

Preparing trout 

Important rule: always cook trout (and other fish) before eating it. The 10-minute rule is one way to cook trout by baking, grilling, poaching, broiling, and steaming. Measure the trout at its thickest point. Cook the trout for about 10 minutes per inch, turning it halfway through the cooking time. For example, a 1-inch trout steak should be cooked for 5 minutes on each side for a total of 10 minutes. Double the cooking time for frozen trout. However, this rule should be used as a general guideline, since fillets often do not have uniform thickness.⁷

Precautionary measures: what to look out for

Allergic reactions

Some individuals may experience intolerance or allergic reactions to trout. Symptoms may include a skin rash, stomach cramps, runny nose or headache. You should take precautions, especially if you eat trout for the first time or offer it to other people. If you have any doubts, it’s better to ask advice from a doctor or nutritional specialist. People who have an allergy to one type of fish often react to other types. Cooking fish does not reduce the likelihood of allergic reactions.²

Overconsumption and monotonous diet

You should also avoid large portions and a monotonous diet based mostly on trout. Firstly, large portions and a monotonous diet may lead to an imbalance of nutrients and increase the risk of allergic reactions and other diseases. For example, oily fish is often high in pollutants, which may be harmful in higher doses. In addition, excess consumption of a limited variety of fish can decrease the population of these fish due to overfishing and damage the environment.²

Medications and supplements

If you take any medications, carefully read the instructions for their use. Some medicines are incompatible with certain food products. If you take fish liver oil supplements, remember that they contain lots of vitamin A. Excessive, long-term consumption of vitamin A could be harmful. Total intake of vitamin A should not exceed 1.5 mg per day from both food and supplements. Pregnant women should avoid taking supplements with vitamin A.²

FAQs

What fish is best for muscles?

Trout is an oily fish that contains long-chain omega-3 fatty acids and is rich in vitamins and minerals. Therefore, trout can help you improve your overall health and support your muscles. Omega-3 fatty acids are essential for muscle development and health; they can improve protein synthesis and reduce protein breakdown in muscles.

Is it OK to eat trout every day?

Due to its relatively low calorie content, trout is well suited to most diets. Trout is rich in vitamins and minerals, as well as fatty acids, so it can diversify and saturate your diet with healthy nutrients. However, you should also avoid large portions and a monotonous diet based mostly on trout or any other kind of fish.

How do you enjoy trout in a meal?

Trout can be a component of salads and main dishes. It can be easily combined with vegetables, fruits, grains, olive oil or any dressing of your choice, which enhances its health benefits. Make sure that the trout has been stored and prepared appropriately. Always cook the trout before eating it.

Summary

A diet that includes trout can improve and support the health of your muscles due to its rich nutritional profile with polyunsaturated fatty acids, vitamins and minerals, and low-calorie content. Trout can easily be incorporated into a healthy, balanced diet, helping you stay healthy and strong.