Is tuna good for weight loss?

The quest for a balanced diet that supports your weight loss efforts while meeting daily life's demands and nutritional needs can be a real challenge.

Tuna, a versatile and widely available fish, often finds itself at the centre of discussions on weight and health.

But is this saltwater fish truly a diet superhero, or are there pitfalls to watch out for?

In today's article, we'll dive into the heart of this question, examining the nutritional properties of tuna, whether it can help with weight and fat loss, and the best (and easiest) ways to incorporate it into your diet.

The nutritional benefits of tuna fish

Tuna is a powerhouse of nutrients. It's loaded with high-quality protein, omega-3 fatty acids, selenium, and vitamin D.

With such a rich nutrient profile, eating tuna can be great for maintaining your heart health, reducing inflammation, boosting your immune system, and more.

Protein

Did you know that tuna is a complete protein? Or that for 100 grams of tuna, you get 29 grams of protein (and only 130 calories) [1]?

Protein is well-known to be the most satiating macronutrient, making you feel fuller for longer and preventing you from overeating or snacking between meals.

If you want to lose weight, eating a high-protein diet with foods like tuna and other lean fish can also help preserve muscle mass, which is key for maintaining a high metabolic rate.

Omega-3 fatty acids

The omega-3 content in tuna varies depending on the type you're eating.

Fresh boneless tuna, for instance, has 25mg of DHA and 3mg of EPA (the two main types of omega-3s), while canned tuna packed in oil has 29mg of DHA and 8mg of EPA [2].

Regardless, these healthy fats can improve your heart health and are associated with a reduced risk of obesity [3].

They are also believed to have a positive impact on 'brown fat' activation.

Brown fat is a type of fat that burns calories to produce heat and keep you warm in cold temperatures; and studies suggest it may reduce the risk of certain obesity-related conditions [4][5].

Selenium

Selenium is crucial for your thyroid health, helping to regulate metabolic functions, such as your body's growth and how many calories you burn.

It also provides powerful antioxidant benefits, can help keep your heart healthy, and can boost your immune system [6][7][8].

Yellowfin tuna is an amazing source of selenium, packing 92mcg of this essential nutrient per 85 grams (while canned tuna in brine contains 69mcg per 100 grams) [9][10].

Vitamin D

Finally, tuna is high in vitamin D, offering 270 IU per 100 grams (that's nearly half of the daily recommended intake!) [11][12].

This vitamin is super useful for those on a weight loss journey, as vitamin D deficiency has been linked to higher fat mass and obesity [13], but that's not all — it can also support immune function and help regulate your mood [14][15].

Is tuna weight loss-friendly?

When it comes to shedding those pounds, it's not just about the calories you consume but also about the quality of the food you eat.

Tuna is indeed low in calories but high in nutritional value, which makes it a great addition to meals or snacks that will keep your caloric intake in check throughout the day.

Here's how that plays into a weight loss strategy:

• Calorie content: Canned tuna, especially packed in water, can provide a significant amount of protein for relatively few calories. This can help you maintain a calorie deficit, which is the foundation of weight loss.
• Nutrient density: A diet high in nutrient-dense foods like tuna will leave you feeling more satisfied, as your body is getting all the essential nutrients it needs, making you less likely to crave high-calorie, low-nutrient foods.

But what you eat is only part of the equation when it comes to weight loss.

If you feel like you're doing everything right — choosing all the right foods, moving your body regularly, getting 10k steps in every day — but your weight still doesn't seem to budge, it might be time to get some extra help.

Designed by UK clinicians, Juniper’s Weight Reset Programme can help you achieve your weight loss goals, and see you stick to them for life.

It combines breakthrough weight loss medications (Wegovy or Mounjaro) with ongoing support from health experts (including dietitians and nutritionists), as well as access to a community of like-minded women on a similar journey to yours.

Is tuna good for losing belly fat?

Belly fat, or visceral fat, is a concern for many. It's not just about the way it looks; it's also a risk factor for various health issues. So, can tuna help you burn stubborn stomach fat?

We'll start by saying that you can't spot reduce fat, meaning you can't control where your body loses fat.

However, tuna can be a useful tool for burning body fat in general, thanks to its omega-3 and protein content.

The healthy fats slow down digestion and help you feel more satisfied after eating, while protein can reduce cravings and the desire to snack at night — both common culprits for increased belly fat [16].

In fact, protein has the highest thermic effect of all macronutrients, meaning your body has to work harder to break it down and ends up burning more calories in the process.

What is the tuna diet?

The tuna diet is an eating plan created by bodybuilder Dave Draper, where you only consume plain tuna and 2 litres of water for 3 consecutive days.

After those 3 days, you can add chicken, leafy greens, steamed non-starchy veg, fruit, and low-fat dairy foods to the menu.

This diet is said to promote rapid weight loss, but before you start stashing cans of tuna in your pantry, it's important to consider the fact that this is an extremely restrictive approach to eating.

This means that:

1. There's a high chance of gaining the weight back once you stop the diet
2. The severe calorie restriction will likely make you feel hungry, making the diet difficult to stick to
3. There's a whole array of vitamins and minerals that your body won't get while you're on the diet

In other words, the tuna diet isn't healthy or sustainable. Plus, there's no scientific research to confirm its efficacy.

If you're hoping to lose body weight, you're better off working with a nutritionist who can create a personalised meal plan based on your current body weight, individual caloric needs, and weight loss goals.

Can you eat too much tuna?

So, you know that eating only tuna isn't a good idea. But is there a thing as too much tuna?

To answer this question, we need to consider the levels of mercury — a heavy metal that can be toxic in high amounts — that tuna contains.

High-mercury tuna, such as big eye and albacore, should be consumed in limited amounts, especially for women who are pregnant or may become pregnant, as mercury can impact the development of the baby's brain and nervous system [17].

Instead, opt for skipjack tuna or light tuna, both of which are typically lower in mercury.

Ultimately, it is important to incorporate a variety of protein-rich foods into your diet and avoid the overconsumption of any one type.

When we're talking about tuna, this is important not only to keep your mercury intake under control, but also to guarantee a balanced intake of all essential nutrients.

Ways to add tuna to your diet

Tuna is a super versatile fish, so there are many ways to incorporate it into your diet. Here are a few of our favourites:

• Have a tuna steak for lunch (or dinner). When responsibly sourced, fresh tuna steaks can be a delicious and nutritious meal. Grill, bake or sear them lightly to retain the health benefits without added fats, and have some veggies on the side for extra vitamins.
• Add canned tuna to salads and sandwiches. Perfect for when you need a super quick protein boost, canned tuna is a staple in many pantries — and for good reason. If you want to keep the fat and calorie content low, make sure to grab tuna that is packed in water and not oil.
• Have it on bread. Tuna on toast (or on rice thins) is a great snack or light lunch, and you can use it straight from the can or sauté it with some garlic and a drizzle of olive oil for extra flavour.
• Mix it in your scrambled eggs. We all love a scramble for breakfast, but why not make it a little bit more exciting with some tuna and a bit of cheese?
• Make tuna salad. You can't go wrong with a tuna salad — simply mix the fish with mayo, dijon mustard, celery, red onion and parsley, and eat it wrapped up in lettuce, in a sandwich, or even as is [18].

Tuna is a great food for those on a weight loss journey, thanks to its high protein content, nutrient profile, and overall health benefits.

To reap these benefits, enjoy the delicious fish as part of a balanced diet, be mindful of portion sizes, and choose lower-mercury varieties.

Image credit: Getty Images