Being overweight is a clear-cut case of too much of a good thing, and we don't mean too many Snickers bars. We mean too much dopamine, a feel-good chemical that gets released in your brain when you eat something delicious. Here's the thing: You can get addicted to dopamine.
When researchers compared brain scans of drug addicts and obese people (food addicts), they found that the brain's reward centers in both groups don't light up well. The centers look like dim bulbs in a flashing Vegas sign. Why?
Here's the short version: When you eat, say, a doughnut, your brain releases pleasure-giving dopamine. At this point, many people walk away satisfied. But for some people (maybe you?), the desire to repeat the pleasure (more doughnut! more dopamine!) is too strong to resist. So you eat more doughnuts to release more dopamine. What foods tend to release feels-so-good dopamine? You guessed it: Pretty much anything loaded with fat, sugary carbs and/or salt.
What happens next? Eventually, the reward center in your brain gets used to having all that dopamine around and stops reacting so intensely (the light bulbs dim). Now you have to overeat just to get your normal dopamine high. And you wonder why change is hard.
To break the addiction (and make those dim bulbs light up normally), you have to say no to dopamine-triggering foods. Like quitting smoking, it will take time and guts, but evading those fatty, sugary, salty traps will let your dopamine levels return to normal. You'll change your brain, and your body.
New reason to take a family walk
If the tweens and teens in your life are complaining about back pain and headaches, check their screen time — how many hours a day they spend staring at TVs, computers, video games and cell phone screens. There's new evidence that the constant muscle tension from being glued to these gizmos has increased kids' complaints of back, neck and head pain by 44 percent.
More than five hours a day is too much. Yet American teens average nearly 4 1/2 hours a day of TV and computer time before they send a single text message (figure 100 of those a day) or play a video game.
The solution? You. Get 'em moving for an hour a day. It's one less hour they'll spend watching "Jersey Shore" or playing "Final Fantasy VIII." And one more hour for their tense muscles (and yours) to relax. Oh, yeah, you might even talk. Some ways to make it happen:
* Schedule family time-outs. Get hikes and kickball games on everyone's calendar. If you wait until you all have "free" time, well, the economy's likely to recover first.
* Don't get hung up on organized sports. Soccer, football, gymnastics, ice/field hockey, et al., are great but they're not great for all kids, and they're not activities most people play for life. Encourage those that are. You know: biking, hiking, swimming, snowboarding, skating, tennis, golf.
* Be a role model. Kids with physically active parents are more likely to be active. For more tips, see our newest book, "You: Raising Your Child," due Oct. 5.
Weight-loss benefits the scales don't show
Tempted to swagger a little after losing weight? Go ahead. That itch to do a happy dance could be your body celebrating two invisible benefits of eating light and exercising regularly — payoffs it may think (even if you don't) are more vital than flat abs:
* Turbo-charged immunity. Cutting back calories by as little as 10 percent for six months can boost your immune strength up to 50 percent, according to one new study. When you eat less, your T cells — white blood cells that fend off diseases — become more numerous and vigorous. Cutting more calories (30 percent) causes the biggest gains.
* Teenage muscles. One reason you can't do the Watusi the way you did at 16: Links between nerve cells and muscles fray over time, allowing some muscle to die. But if lab mice are a good example (and they often are), eating less and exercising more brings those links back to life. Turns out that seriously cutting calories stops the damage, and exercise restores it.
You don't have to go hungry to get benefits like these. Just choose lots of water-filled fruits and veggies, which fill you up without filling you out. Think melon, tomatoes, cucumbers, greens, carrots, grapes, oranges and radishes. Broth-based soups and nonfat milk help, too.
A grain that makes you skinny
Even though there's a wide world of whole grains out there, it's easy to get in the same-old-same-old rut (steel-cut oatmeal? air-popped popcorn?).
Try something new, such as barley, quinoa, buckwheat and whole-grain bulgur. Here are some barley qualities:
1. Barley is teeming with beta glucan, a soluble fiber that mops up lousy LDL cholesterol.
2. The soluble and insoluble fiber in barley urges blood pressure down to the ideal: 115/75.
3. Barley's fiber bonanza expands in your stomach and (this is the skinny part) makes you feel full for hours.
4. Barley, like many whole grains, steadies blood sugar and fights diabetes.
5. There are lots of ways to serve it: straight up as a hot cereal; cooked and tossed into soups, curries and salads; baked in puddings. Plus, barley mixes brilliantly with parsley, mint, tomatoes, garlic and olive oil to make the classic Middle Eastern salad dish tabbouleh.
The smartest workout for you
Do you have more trouble getting up early to walk than a teenager on a Saturday morning? If you'd rather snooze than hop on a treadmill or take a walk in the park, change what you're doing.
The difference between pulling the covers over your head and getting up ready to roll comes down to fun. When you do something you love, you get so distracted that you forget you're "exercising." That's the opposite of what happens when you just do what you've been told — by us or anyone else.
OK, we know "Walk 30 minutes a day" is practically our mantra. We love walking, like 30 percent of adults. And physical activity is the best way we know to erase stress, increase memory and avoid heart disease, stroke and cancer, not to mention impotence and wrinkles.
But we bet our pedometers that avid tennis players would rather do footwork drills than walk. And that people who want to be top speedsters in their spin class will hop on their bikes with a smile.
If you haven't found a fun activity yet, keep looking. Try a Zumba class, rollerblading, urban rebounding or all three. (Variety is spice for your mind and your muscles.) Think back to activities you loved as a kid. Were you a double-dutch champ? Buy a beaded rope and start skipping; teach your kids how to do jumping jacks. Then, next time you hear us say, "Walk 30 minutes a day, no excuses!" grab your rope and blow us off.