Skim milk still has a lot of protein.

I consume a lot of milk but whole milk can be unpalatable so I mostly drink low-fat, which still has some fat and a lot of protein:

    There are 102 calories in 1 cup of 1% Fat Milk.
    Calorie breakdown: 21% fat, 47% carbs, 32% protein.

It also naturally contains calcium and vitamins B and D.

http://www.fatsecret.com/calories-nutrition/generic/milk-cow...

The problem with nuts is that a reasonable serving is very, very small. If you get people to actually buy and take a decent (calorie wise) serving and eat it slowly, it works great. But it's all too easy to eat a 800kcal-1000kcal bag of nuts without thinking about it.

I think a huge part of the problem in general is large packs of food. Ready-made sandwiches in packs with 800-900kcal, for example, or nuts or high-calorie drinks sold in quantities that ought to be anywhere from 2-3 to 10+ servings. Ready-meals that comes only in massive portions that might work ok if you're buying it to split 2 or 3 way, but that are often horribly oversized if you eat alone.

It's all great and economical when you're buying stuff to put in the cupboard and have the willpower to resist eating larger quantities, but clearly we can see that people don't. And unfortunately there's little reason for most manufacturers or supermarkets to offer smaller alternatives, as we're too easily seduced into buying the larger packs.

Personally I found my soda intake dropped substantially after I started buying my weekend soda "allowance" in 250ml bottles instead of 0.5l or 1.5l bottles, for example. And a lot of my other diet maintenance boils down to picking smaller containers, smaller plates, smaller glasses for everything except water.