If you want to "feel full" you need to eat a decent volume of food. To do that without gaining weight, you need to choose foods that are low in calories. Vegetables are the best foods for volume to calorie ratio and fats are the worst. Part of this is simple math: fat is 9 calories per gram and carbohydrates are 4 calories per gram. The other part of it is water. Many vegetables have a very high water content, which fills space in your stomach, but doesn't add to your caloric intake. The next time you're deciding what to eat, try to keep your volume to calorie ratio to the side that won't derail all of your efforts at staying healthy and fit.
Passionate runner since 2009. After ending marathon training in 2011 due to injury, she returned to run the Chicago Half Marathon and the Bank of America Marathon in 2012. Now working on better overall fitness and faster event times in 2013.