Tuna Fish Diet Plan

Although not a formal diet program written in a book, the tuna fish diet plan circulates on the Internet and through dieting circles because of its promised quick weight loss and relatively short duration. One proponent of the diet plan, professional bodybuilder Dave Draper, recommends following the plan for three days. Medical professionals at the Cleveland Clinic advise against following a fad diet such as the tuna fish diet 4.


Draper advocates the tuna diet plan as a way to lose weight and retain muscle tone while preparing for competitions. On the three-day tuna diet, you drink large amounts of water and eat canned tuna fish six times each day. The amount of tuna fish you should eat varies, depending on how much you weigh. Draper recommends multiplying your body weight by either 1.0 or 1.5 to determine how much protein you should have. If you weigh 150 lbs., you would need between 150 to 225 g of protein a day.

Protein, Nutrients and Calories

Tuna fish is a high-protein, low-calorie food that has no carbohydrates. If you want to consume 150 g of protein in tuna, you would need to eat about 21 ounces every day for three days. If your protein requirements are 225 g a day, you would need to eat about 31 oz. a day. The 21 oz. of tuna fish contains 693 calories, and the 31 oz. contains 1,023 calories. Other nutrients in tuna fish include a trace of fat, 3 mg of calcium, 96 mg of sodium and a small amount of vitamin B-12 in each ounce. Consuming 20 oz. of tuna that is canned in water gives you over 1,900 mg of sodium for the day.


Following a tuna fish diet, even if just for three days, may cause you to experience fatigue or stomach upset because of the extremely low-calorie nature of the diet. If you lose weight during your tuna diet, it may be mainly water weight. When you eat a diet very low in carbohydrates, your body often goes into ketosis. This condition occurs as the ketones in your body increase. As the ketones increase, you lose water weight and also risk damaging your kidneys, if the ketosis state remains for a long time. The U.S. Environmental Protection Agency recommends that women who are pregnant, or contemplating pregnancy, and young children limit their consumption of canned light tuna to 12 oz. per week because of the mercury content in tuna.

Healthier Strategies

Instead of following a fad tuna diet plan for three days in the hopes of losing weight quickly, use small amounts of tuna fish each day as either a snack or as part of your lunch or dinner meals. If you want to eat more protein while losing weight, consult your doctor for safe protein levels. Healthy ways to eat tuna fish while dieting include mixing 3 oz. of tuna with 2 tbsp. of fat-free Greek yogurt for a tuna salad, grilling a 4 oz. piece of tuna steak or adding 2 oz. of canned light tuna to a pasta and vegetable salad.