Keeping the ketchup and mayo in the cupboard (or better yet, in the grocery store) can save you lots of calories. You probably know that. What you might not know is that ditching the condiments can help you eat less.

One small study found that fries with ketchup and brownies with a topping caused eaters to consume 25 to 40 percent more of these fattening foods -- not because the extras made the food taste better, but because they increased the time it took for the palate to get tired of the taste of the food.

Going condiment-free isn't the only strategy for cutting down on your consumption. You can minimize the variety in meals -- aim for a few fresh flavors and maybe even eat the same lunch every day, says Dr. Mehmet Oz. Also, before a meal, eat small amounts of healthy, unsaturated fat (olive oil, nuts, avocado, fish) to slow the rate at which your stomach empties -- this will cause you to feel fuller faster.