I am very vulnerable to cold, but I don't eat properly.
After my husband died, my friend started staying round a bit, and basically observed me. Then she kicked my butt about my eating habits.
I now have Weetabix and milk in the morning, and try to have a proper lunch and dinner.
I also try to remember to treat myself to anything I want, like cream cakes and profiteroles in between, trying to make up the calories.
But the most important thing is to have orange juice, at least a bit, with or near mealtime. Apparently, vitamin C helps you absorb iron from food, and I used to tend to be on the anaemic side, and this has cleared up just with that. Of course, having more iron in the blood will naturally make my body more efficient.