I have worked in the grocery business for 21 years and have found that the healthiest looking people shop mostly the perishable departments. Steer clear of the aisles where the overprocessed foods lurk unhealthily. Stick with fresh produce, meat and seafood, ice-cold dairy products and even the freshly baked artisan breads in the bakery. Of course the old-fashioned oatmeal and a few yummy nut butters reside in the aisles but don't let their redneck cousins, the poptarts and sugary cereals tempt.
This "whole foods" concept of eating leaves you fuller and NOT craving all the additives. White bread is equivalent to eating PASTE!! The condiment aisle is a slippery area too....so be cautious!