Tuna Diet – Everything you need to know

Are you looking for a new, healthy option for your diet?

Do you like fish?

Are you looking for an economical way to eat lunch or dinner every day – while staying fit and healthy?

If you answered “yes” to any of these questions, then read on to learn how you can begin to incorporate tuna fish into your diet.

Adding a tuna meal to your eating regiment is fast, easy – and if you can take that fishy smell — delicious!

Here’s how to do it for your next meal…

egg salad

What are the Pros and Cons of a Tuna Diet?


There are many pros of incorporating low-sodium or no-salt tuna into your diet.

For example, did you know:


  • Tuna is packed with protein—about 17 grams per serving.(1) That means you’ll fill up quickly and stay hungry longer than you would if you were eating only fruits and vegetables, for example. In fact, studies have shown that people who consume a high-protein diet with normal carbohydrate intake are less likely to overeat and gain weight.(2,3,4)
  • Tuna is rich in vitamins.(1)
  • Tuna is a natural product of the sea.
  • Tuna is a low-calorie option. A 3-ounce can of tuna, for example, has only about 70 calories in it.(1)
  • Tuna is an economical choice at about $2 a can for a low-sodium option packed in water.
  • Tuna is a quick and fast lunch or dinner. All you need to do is add a few condiments, mix, and you’re ready to go!
  • Tuna can be a go-to pick-me-up for any meal. Forgot your lunch? Just always have a can of tuna in your desk drawer!


There are cons of eating tuna, but the pros far outweigh them.

Among them are:


  • Tuna – like all fish in the sea—contain some trace of mercury. The FDA has long warned of this – but mercury toxicity only is a real problem for people who eat tuna every day over a long period of time, and even then it may not affect a person.(5) It really depends on the person and their health combined with their genetic makeup. The key with eating tuna is to eat it in moderation.
  • Tuna is smelly, but then again fish is smelly! If you’re preparing your tuna in the office work room, it might be offensive to some people.
  • Canned tuna is packed in both water and oil. For optimum health benefits, choose the tuna that is packed in water and does not have salt added. You can add flavor to tuna by using condiments.
  • Eating tuna every day is going overboard. Make sure you are balancing your meals with the FDA’s recommended portions of fruits, vegetables and other proteins.(6,7)
  • Without exercise and healthy eating, tuna alone isn’t going to cause you to lose weight. Losing weight is a holistic process.

How Long Should I Incorporate Tuna Fish into My Diet?

As mentioned above, the key to losing weight and staying healthy on a tuna diet is to incorporate it slowly and with moderation.

That means you should try many different kinds of lean protein – such as chicken and other fish – in combination with tuna.

To give you an example of a plan you could follow to safely incorporate tuna into your new diet, consider this plan:

One-Week Tuna Diet Plan Sample

cheese and tuna

Exercise is key in this plan, so make sure you are continuing to do at least 30 minutes of exercise every day throughout the week.

If you prefer high-intensity workouts, move your regime to every other day.


  • Start your morning with a brisk 30-minute walk following by an energizing all-fruit and peanut butter smoothie.
  • At lunch toast bread and prepare a 3-ounce can of low-sodium tuna in water with a teaspoon of homemade mayonnaise.
  • For dinner, bake chicken and a side of your favorite green vegetable.


  • Bring back that brisk walk or jog in the morning followed by a low-fat yogurt and granola.
  • For lunch, eat a big, leafy salad with grilled chicken.
  • For dinner, grill or broil your favorite fish with a side of green vegetables – your choice.


  • In the morning, try a piece of toast with peanut butter followed by baked chicken tenders and salad for lunch.
  • For dinner, grill a tuna steak and add leafy green veggies.

As you approach the end of the week, try a different protein other than tuna.

For example, try a white fish such as cod or a healthy-fat-rich fish such as grilled salmon.


  • Exercise, eat a protein bar for breakfast, and finish off lunch or dinner with veggies and chicken or fish.

On Friday, take a rest day from exercise or get in a quick walk.


  • Eat peanut butter toast for breakfast, and for lunch make a salad using tuna drained from the can sans condiments. Add a little oil and vinegar so that the tuna isn’t too dry.
  • As an alternative, consider incorporating a tuna poke bowl into your lunch regime. Raw tuna has all of the benefits of canned and grilled tuna as far as the protein content goes -- but you really need to like raw fish for this option.
  • For your Friday night meal, eat a big salad with a lean protein such as grilled chicken.

The weekends are for a little splurging, but if you really want to lose weight, now is not the time!

Instead, make your diet a little more colorful and fun on the weekends.


  • After your morning walk, make a new smoothie for breakfast.
  • Prepare a chicken wrap for lunch and grill a tuna steak for a salad for dinner.

Get ready for another week by preparing some of your tuna meals ahead of time.

Cooked tuna will keep for a couple days, so you could prepare a few cans of tuna for tuna salad for lunches early in the week.

Bake a few tuna steaks for salad toppings or a main meal.

You’ll be ready to eat a healthy, low-sodium protein along the way without having to think too much about it if you do a little meal prep!


  • One egg (hard-boiled, one slice toast & one banana for breakfast
  • For lunch one-half cup tuna OR one cup cottage cheese & one cup leafy greens.
  • One cup of broccoli & low fat cheesecake for dinner

How Much Tuna Should I Eat in One Sitting?

This is an excellent question considering how we have been stressing the importance of eating tuna in moderation.

To get the most benefit out of tuna in your diet, you should eat only about a 3-ounce can at a time.(8)

That’s because tuna in this iteration is packed with protein while still keeping the calories low.

Keep in mind that you’ll probably be adding condiments to your canned tuna, so you’re going to add a few more calories.

If you want to keep your caloric intake as low as possible, the 3-ounce can is the way to go. Once you bump it up to the 12.5-ounce can, you’re talking about nearly 300 calories in a sitting.


What Should I Be Looking For on a Tuna Can Label?

The caloric content of canned tuna change dramatically if you are not reading the labels of your tuna. Not all tuna cans are alike!

So become a good label reader.

For example, you want to buy tuna that is packed in water and has a low salt content.

On the label, you are looking for “sodium” and any other ingredient that may add calories or additives you really don’t need.


Are There Any Other Benefits of Tuna I Need to Know About?

In fact, yes there are!

People who eat fish — including tuna — can reduce the pain and inflammation they feel caused by conditions such as rheumatoid arthritis, according to a study published in Arthritis Care & Research Journal.(9)

If you find yourself in this situation, you can lose weight and manage pain in your body simply by incorporating tuna into your weekly diet about three times a week.

Be creative with your meals and remember everything from grilled tuna steaks to tuna salad to tuna poke bowls count!


Are You Ready to Try Tuna?

Now is the time to try eating tuna and making it part of your healthy eating diet.

Tuna does take some getting used to if you don’t particularly like fish – or the smell of fish – but there are ways to get around that.

For example, tuna fish that has been packed in oil almost eliminates that smell. Now, the oil is going to pack on some calories and fat – but you won’t have the fishy taste or smell.

If you’re new to tuna, start with a small amount – such as a tuna fish sandwich or salad – and work your way up to other types – such as a tuna steak.

Remember to get the most benefit out of eating tuna by choosing a low-sodium or no-salt version.

Also, remember that tuna has mercury in it – and too much of it can lead to poor health and detrimental effects.

So, moderation in everything!

You should talk with your doctor before beginning any major dietary change.