We always think that all fruits and vegetables are foods that naturally help us watch our weight, foods like:
Although these may be low-calorie, they're sweet and watery, two Kapha traits that according to ayurveda will actually encourage the body to increase it's "earthy" and liquid qualities (fat, water). In ayurveda, like increases like so consuming foods that are heavy liquids (regardless of low calories), your body will, in essence, get heavier and liquidier by increasing fat and retaining water.
Foods that decrease Kapha have opposite qualities to Kapha; Kapha is sweet, liquidy and heavy, so foods that help with weight are bitter, dry and astringent. That means foods like apples, pears and apricots, which are dry, and leafy greens, asparagus, parsley and basil, which are bitter, and artichokes, pulses and lentils which are astringent.