Do You Really Know When You're Full?

In a super-sized world, it can be tough to monitor portion sizes. New research, however, found that it might not just be the big plate at your favorite restaurant. Instead, a team of researchers have found that some rat brains are naturally hardwired to be more vulnerable to obesity than others.

In studies on lab rats, Professor Tamas Horvath and colleagues found that some rats gained weight more easily than others, despite being on identical high-fat diets. They determined that this was due to sluggish brain neurons, which in some rats were slower at alerting them to the fact that they were full, ultimately leading to habitual overeating and eventual obesity.

"These observations add to the argument that it is less about personal will that makes a difference in becoming obese, and it is more related to the connections that emerge in our brain during development," Horvath said in a statement.

However, research done in rats does not always translate into humans, so don't dive into a box of donuts just yet and blame your brain chemistry. Also, just because genetics play a role, it doesn't mean your fate can't be altered by your environment. If you have trouble feeling satiated even with large portions, there are many easy strategies to help your brain know that your stomach is getting full.

We asked Andrea Giancoli, spokesperson for the American Dietetic Association, for her tips on helping your brain recognize fullness without consuming a bunch of extra calories.

•Start with a salad or soup. "Research has shown that high-water content foods -- greens, cucumbers and tomatoes, for example -- help fill us up so we eat fewer calories total at the meal," Giancoli said. But make sure the dressing is low in fat and calories and the soup is broth based, not creamy.

•Take it slow. "If you suspect you're one of those folks who has sluggish nerves, slow down your eating habits to give your stomach more time to feel full," she noted. "Take a rest between bites, put down your utensils after every bite and don't pick them back up again until you've finished chewing your last bite.

•Watch those portions. "Use smaller plates, serve yourself smaller portions and share meals when you go out to eat or put half of your restaurant meal in a to-go box right away," she said. "Tell yourself you can always have seconds if you want, and if you really are still hungry, wait five to 10 minutes before you have more."

•Eat the veggies on your plate before the meat or starches. Giancoli said there are two reasons for this: to fill you up and to make sure you eat them.

•Drink water. "Having big sips between bites will fill your belly with water volume, which leaves less room for calories. Plus, it forces you to take a break between bites," she pointed out.

•Focus on fiber. "Fiber helps to fill you up so you eat less," she insisted. You can get your fill of fiber from nutritious fruits and veggies, so make sure you're eating lots of them.

These tips are definitely something to chew on (slowly, of course). Got any tips of your own?