A quick Google reveals plenty of “no salt added” Tuna brands
You can freeze a container of yoghurt overnight and by lunchtime it will be thawed. And it will keep the other things in youe bag cool.
Heck, assuming your lunch leaves a fridge in the morning and is sitting in an air-conditioned office until lunch, even sliced lunch meats should be fine. I regularly bring in roast beef or turkey and usually don’t refrigerate it. I wouldn’t do it if the lunch was, say, sitting exposed in a car while doing fieldwork in August in New Orleans, or something, but no problem in an office.
And even if it was a car in August in New Orleans, a small lunchbox and a minimal cooler pack would probably be enough. Overkill in an office, but if you really want to be reassured you could go that route.
Edemame. Unfortunately, not too tasty without salt.
Greek yogurt and hardboiled eggs, whole or whites, depending on your preference. Trader Joe’s has greek yogurt really cheap, otherwise check Target or some of the new, cheaper greek offerings at the grocery (Fage is insanely overpriced).
Just stick em in a lunchbox (this one by BuiltNY is super nice, bestselling on Amazon) and include an ice pack as well (at your local BigBox store) and you’re set to go.
Missed the edit:
ETA: As for protein powders, Muscle Milk Light is excellent (cheapest at Costco but reasonable elsewhere on sale, like Vitacost.com or WallyWorld) as well as Optimum Nutrition Platinum Hydro Whey, which is one of the only recommend protein powders by Consumer Reports. Many others have disturbingly high levels of metals. Muscle Milk Light comes in a variety of flavors and it tastes significantly better in juice-box format.
Or just buy non-fat dried milk. Much cheaper than overpriced protein powders.
Regards,
Shodan
Unsalted almonds work really well for me. I keep a baggie at work and eat a handful a couple times a day when I need an appetite buster.
Except that it isn’t a very good source of protein.
Cite.
Regards,
Shodan
It has more grams of sugar per serving than grams of protein. That, IMO, is not a good source for dietary protein.