There are innumerable benefits to regular exercise and eating well, from a better mood to better sex to a healthier heart to a longer life (not to mention a nicer-looking butt). But just knowing about the good-for-you benefits of exercise and fruits and veggies may not be enough. Have you tried psychological tactics?

Cornell University researcher Brian Wansink studies how and what we eat for the White House, where he is in charge of making changes to the dietary guidelines for the United States. He was appointed by the White House to head up changes to U.S. dietary guidelines. Wansink has also written two books: "Mindless Eating: Why WeEat More Than We Think" and "Slim by Design: Mindless Eating Solutions for Everyday Life."

Turns out that we overeat not because we're hungry, and we forget to exercise not because we just don't want to. In both cases, Wansink says it's due to bad habits and triggers. He says we don't do enough to protect ourselves — and to motivate ourselves — using our strongest body part: our brain.

In what he calls the "mindless margin," Wansink discovered that you can eat 20 percent more (or less) and not really notice it. (That would definitely account for that extra 20 pounds some of us are toting around, right?) In his book, he writes: "If we eat way too little, we know it. If we eat way too much, we know it. But there is a calorie range — a mindless margin — where we feel fine and are unaware of small differences. That is, the difference between 1,900 calories and 2,000 calories is one we cannot detect, nor can we detect the difference between 2,000 and 2,100 calories. But over the course of a year, this mindless margin would either cause us to lose 10 pounds or to gain 10 pounds."

In an experiment detailed in the video below, he describes how he rigged a modestly sized bowl of soup to keep refilling as people ate. With more than 120 people enjoying unlimited soup, only a couple figured out what was going on. And overall, people ate 73 percent more soup when they couldn't tell how much they were eating. When asked if they were full, people said, "No, how could I be full? I have a half a bowl of soup left!" And so proving that we do indeed eat with our eyes and not with our stomachs.

It's a profound realization if you are one of the people who only knows you are finished eating when your plate is empty (no matter what's on it) or if you eat chips out of a large bag or if you eat straight out the ice cream carton — and who hasn't done that? Here are some tricks to help.

Trick 1: Portion out your food. Never eat from the container. Think about using smaller bowls and plates for your food at home too. When dining out, plates tend to be large, so immediately decide how much you're going to eat and set the extra aside for a doggy bag. All of these actions mean you will make a conscious decision about exactly how much you're going to eat. Don't let your subconscious take over.

Trick 2: Hide the yummies. Wansink's research has found that we eat what we see. People who have soda sitting out in their homes weigh on average 25 pounds more than people who don't, and those who have fruit sitting on the counter weigh 8 pounds less. If breakfast cereal is out, you probably weigh 19 pounds more. If you have cookies and cake sitting out, you likely weigh 8 pounds more. So if you can't get rid of the soda, cookies, candy or other foods, hide them. Literally, out of sight, out of mind. Ask your family to help you if they tend to leave tasty snacks out. Research has shown that we can only make so many good decisions in a row before the mental muscle tires out, so not tempting yourself in the first place will help.

And you can use this trick to your advantage too, putting healthy snacks at the front of the fridge or cabinets or out on the counter. And get that candy off your desk at work. Those who had bowl of sweets weighed 15 pounds more than their coworkers who didn't.

Trick 3: Make getting food harder. Those who ate with serving dishes on the table ate almost 30 percent more at a meal (it's right there, so easy!) Make getting seconds more difficult — at least having to stand up and cross the room to get them. If you are in a buffet situation, be aware. Wansink writes: "Slim people even acted differently after taking their food. They trotted back to faraway booths along the walls, and — here’s what’s cool — 73 percent faced away from the buffet. Heavy diners did the opposite. They sat at tables that were on average 16 feet closer to the buffet."

Trick 4: Plan what you eat. This is easier to do at home than when you're eating out (where many of us find eating moderately a challenge). But planning what you eat, wherever you are, will help you make smarter decisions. Wansink writes in "Slim By Design": "Slim diners 'scouted' out the buffet before grabbing a plate — before even picking up a plate, 71 percent of them walked around and scanned the salad bar, the steam trays holding fourteen seemingly identical chicken dishes, the sushi station, and the dessert bar. Only after they figured out the lay of the land did they grab their plate and swoop down to cherry-pick their favorites, with an eagle eye on the stir-fry. Heavier diners did the opposite. They were twice as likely to charge ahead to the nearest stack of plates, take one, and fill it up. They didn’t skip to the foods they really liked. Instead they served themselves a bit of everything they didn’t hate."

Trick 5: Grocery shop when you aren't hungry, and stay away from the four C's. Cereal, candy, crackers and chips are all way too easy to eat too much of if you are trying to lose weight and have any trouble at all with impulse control (that's most of us). Cutting them out entirely, or saving them for a special treat as opposed to food you eat daily, will help with weight management over the long- and short-term. Shopping when you are hungry is when you are most likely to buy something that you want to eat right away, like these less-healthy processed foods.

Trick 6: Read labels. Being informed does make a difference. "Label users who did not exercise displayed a slightly greater likelihood of weight loss than those who exercised but did not read food labels," writes Wansink.

Trick 7: Reduce variety. The more types of food you have on your plate or in the pantry, the more you are likely to eat. Wansink advises having only two types of food on your plate at any one time. If you want to try something else, at least you'll have to get up to serve yourself more. Try to keep just one type of treat in the house (dark chocolate is packed with antioxidants and satisfies in small amounts), so you don't have a choice, and if you are eating at a restaurant, stick with your dish and don't share appetizers with friends.

Trick 8: Make a new habit and let it sink in. Don't try to make all the above changes at once. (I'd start with getting treats off the counters and cutting out soda to begin.) Wansink writes, "People who most successfully lost weight made only one or two changes but stuck with them day after day — an average of at least twenty-five days a month. Unfortunately, the people who didn’t lose weight often tried to tackle too much all at once. They tried to change everything, and most gave up within a month."

Trick 9: Make it easy. Put your workout gear out before you go to sleep, put your healthy lunch together the night before, and hide the treats when you're in a good mood. Make it as easy to change your habits as possible. The easier it is for you to do the healthy thing, the more likely you are to do it. (But you knew that, right? So put it into practice.)

Losing weight is a challenge, and the best way to do it is slowly, over time. (That's how most of us gained it in the first place, after all). The upside of reversing bad habits is that the new healthy habits are...habits. And will stick with you for the duration.

Starre Vartan ( @ecochickie ) covers conscious consumption, health and science as she travels the world exploring new cultures and ideas.

Use psychological tricks to drop the pounds
Sure, you've tried everything to lose weight — but have you put your brain to work?