I've always been aware of the effect of food on my mood—for example, that depressed feeling I get an hour after eating too many Oreos or the snappish Mr. Hyde in me that emerges when I fast all day for religious holidays. But lately I've noticed mood changes even with subtle changes in my diet; I get tired and sluggish, for example, when I eat too much hummus and pita bread for lunch. And I felt strung out last Sunday just by delaying my usual lunchtime by an hour while getting my kids fitted with boots at a local ski resort. I immediately felt calmer after I wolfed down a cheese sandwich on whole-grain bread.
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While it may take years for us to develop heart disease from Big Macs and fries, you say the link between food and mood is immediate; how is that possible?
It all comes down to brain chemicals and the signals they send enticing you to replenish your fuel. For example in the morning, your body releases a chemical called neuropeptide Y, which signals your brain to eat something starchy, whether it's a bagel, a doughnut, or a bowl of high-fiber cereal. If you eat a starchy breakfast, your brain gets the signal that your blood sugar is higher and will shut off the chemical. If you don't, the chemical stays elevated, fueling carbohydrate cravings throughout the day. And depriving your brain of glucose for too long will make you feel cranky, low energy, and irritable. On the flip side, eating carbohydrates boosts the brain chemical serotonin, which makes you feel happy and relaxed. So it doesn't matter whether I have a doughnut or bran cereal for breakfast to keep my brain happy?
No, it certainly does matter. Thousands of studies have shown that the more real foods people eat, the happier they are and the more likely they are to be lean and free of disease. I recommend eating real food 75 percent of the time. What do I mean by real food? Anything without a long list of ingredients, such as blueberries instead of a blueberry-flavored granola bar, slow-cooked oats instead of instant maple-flavored oatmeal, a baked potato instead of potato chips. In other words, unprocessed foods. So for breakfast, you'll get the most energy by eating a slice of multigrain toast, a bowl of shredded wheat, or a serving of slow-cooked oatmeal. Add a piece of fruit or glass of fruit or vegetable juice. I also recommend getting a little protein—like milk in your cereal or peanut butter on your toast—to keep your blood sugar levels elevated until lunchtime. (Eating a lot of processed sugary carbohydrates cause blood sugar levels to rise quickly and drop quickly, leaving you low energy, hungry, and irritable.) Regular exercise, too, is crucial for keep your mood and energy levels up. [7 Instant Mood Boosters if You're Feeling Sad]
What should I have for lunch to avoid that afternoon slump?
You want your lunch to be light and low-fat. Too much fat will leave you groggy during the afternoon, thanks to a brain chemical called galanin, which is released in large quantities when you eat too much fat, especially during lunchtime. This chemical is responsible for mood regulation, and high levels have even linked to Alzheimer's disease. And studies have shown that those who eat high-fat lunches—for example burgers, tuna salad drenched in mayo, guacamole and chips—eat 50 percent more calories throughout the day than someone who eats a lighter lunch. That's because galanin turns on our cravings for fat. Good lunch choices include large salads with lean protein sources like grilled chicken or fish and just a small dollop of dressing; a bowl of soup with a turkey sandwich on whole-grain bread; a baked bean burrito on a whole-wheat tortilla with fruit salad; peanut butter and jelly on whole-grain bread with soy milk. What should I eat for dinner that won't disrupt my sleep?
Getting a good quality, uninterrupted night of sleep is, of course, essential for being energized and in good spirits the next day, and a proper dinner is crucial for this. Don't have a heavy dinner right before bed to avoid heartburn and indigestion—pretty obvious advice. Watch out for spicy or gassy foods. Stick with grilled chicken, tofu, or fish, accompanied by brown rice or barley and steamed vegetables. Twice or three times a week, try to have a fatty fish like salmon, anchovies or tuna; the omega-3 fats that they're rich in may help stave off depression and even Alzheimer's later in life. If you're a vegetarian, look for foods that are fortified with an algae-based omega-3 fat called DHA. Some milk brands, tortillas, margarines, eggs, and cooking oils are fortified and say so on their labels. [Pregnant? How to Boost Your Baby's Brain Power]
Also, about 30 minutes to an hour before bed, have a carbohydrate-rich snack such as 2 cups of air- popped popcorn or a slice of whole-grain toast with jam. This will boost your level of serotonin, making you feel calm and pleasantly drowsy.
In your book you talk about super mood foods. What are these?
These are 12 foods that pack a huge mood boosting and waist-slimming punch. Many of them keep blood sugar levels stable so you don't have mood and energy swings, or they pack a lot of memory-boosting antioxidants. I recommend sprinkling them into your regular meals and snacks. They include daily servings of:
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