Tuna

Tuna is a popular favorite. Now easy to tote in pop-open cans or pouches, it has become a terrific go-to snack when searching for a fast and easy protein fix. Though there's been some concern about mercury levels in albacore ("white") tuna and tuna steaks, you can enjoy them in moderation (once a week).

• Pair a pouch of tuna teriyaki with a side of baby vegetables such as carrots and tomatoes. 140 calories (6-ounce tuna fillet alone); up to about 240 calories with 2 cups of vegetables.
• Mix a can of water-packed tuna with a little mustard or reduced-fat mayo and stuff into celery sticks. About 180 calories.
• Top an open-faced whole-wheat English muffin with tuna, and two slices of reduced-fat cheese. Broil in toaster oven for five minutes. 300 calories.
• Try the classic Nicoise combination. Toss tuna on a bed of lettuce with hard-boiled eggs, black olives, haricots verts (thin, stringless French green beans) and diced potatoes, then dress with a simple vinaigrette of oil, vinegar and Dijon mustard. 350 to 500 calories depending on portions (not including dressing).

Sardines

Sardines are among the top three healthiest choices when it comes to fish. Packed with healthy omega-3s and calcium, these little fishies should not be ignored. Fear not, the canned-in-water skinless variety is no more frightening than a can of tuna, yet delivers far more nutrition per square inch!