Researchers at Cornell University says shoppers who ventured out earlier in the day between 1 and 4p.m. bought less high-calorie foods than those who shopped between 4 and 7p.m. But the best time to go shopping may be first thing in the morning. That is when perishable foods such as dairy products and fruits and vegetables are most often fresh. Financially, the best day of the week to go shopping is likely Wednesday--that's the day grocery stores start their weekly discount and coupon programs. It's also a day most stores will honor coupons from the previous week, giving shoppers a "discount double day." Saturday is, by far, the busiest grocery shopping day of the week, with 41 million shoppers. Wednesday averages 30 million shoppers, according to the study, making for more room in the aisles.