Canned tuna is a popular, affordable source of high-quality protein. The choice between tuna packed in water or oil is crucial, as the packing medium is the largest factor determining the final nutritional profile. Understanding the differences in fat, calories, and the retention of healthy omega-3 fats is key to choosing the option that supports your health objectives.
Nutritional Comparison of Fat and Calories
The most noticeable difference between the two types of canned tuna is the calorie and total fat content. Tuna packed in oil, typically soybean or other vegetable oils, carries a much higher energy load than tuna packed in water. A standard 5-ounce can of water-packed tuna contains approximately 120 calories, whereas the same amount packed in oil can contain around 280 calories before draining.
This significant increase is almost entirely due to the added fat from the packing oil. The oil-packed version often contains more than double the total fat of the water-packed variety, which usually has less than one gram of fat per serving. Conversely, the protein content remains relatively consistent regardless of the packing medium, providing a substantial amount of muscle-building protein per can.
The added vegetable oil dramatically increases the overall caloric density of the product compared to water, even if the can is labeled “light.” For individuals monitoring their daily caloric intake or seeking to reduce dietary fat, the water-packed option offers a clear advantage.
How Packing Medium Affects Omega-3s
Tuna naturally contains beneficial Omega-3 fatty acids (EPA and DHA), which are important for heart and brain health. Since these compounds are fat-soluble, the packing medium directly influences their retention. When tuna is canned in oil, the added fat acts as a solvent, causing some of the tuna’s natural Omega-3s to leach out into the surrounding oil.
If the oil-packed tuna is drained, the consumer loses a considerable amount of the beneficial Omega-3s along with the discarded oil. Studies have shown that draining oil-packed tuna can result in a loss of 15% to 25% of the original Omega-3 content. In contrast, when tuna is packed in water, the tuna retains more of its natural Omega-3 content because these healthy fats do not readily leach out.
While high-quality olive oil might contain beneficial monounsaturated fats, the common vegetable oils used are often high in Omega-6 fatty acids. This makes water-packed tuna a more reliable choice for maximizing the intake of the fish’s inherent Omega-3s. The final amount of these healthy fats in water-packed tuna is often slightly higher than in drained oil-packed tuna.
Practical Recommendations for Health Goals
The healthiest choice depends on your individual health objectives, but draining the liquid is a foundational step that significantly narrows the nutritional gap between the two options. Draining oil-packed tuna can remove a large portion of the added fat, potentially reducing the total calorie count by over 50%.
For those prioritizing weight management or a lower-fat diet, water-packed tuna is recommended due to its minimal fat and calorie contribution. This variety provides lean protein without the added seed oils common in the oil-packed versions. This makes it the most straightforward choice for maintaining a low-calorie diet.
However, if you choose tuna packed in high-quality olive oil and drain it thoroughly, the nutritional profile moves closer to the water-packed version. Oil-packed tuna often retains a better flavor and texture, and if the can uses olive oil, it can offer some added beneficial monounsaturated fats. For most consumers seeking the highest protein and lowest fat option, water-packed tuna remains the simplest and most consistently healthy choice.