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Special Reports October 2011 Issue

When Snacks Attack

Take charge of what’s become America’s fourth daily “meal” with these strategies for smarter snacking.

If you can’t seem to succeed in your healthy-eating goals, despite nutritious meal planning, maybe the problem is what you eat between meals—snacks. Americans are now eating so much between meals that snacks add up to a quarter of the average calorie intake. According to researcher Richard Mattes, PhD, MPH, RD, of Purdue University, who recently presented a study on the snacking boom (see September 2011 NewsBites), “Between 1977 and 2006, snacking in the American diet has grown to constitute ‘a full eating event,’ or a fourth meal, averaging about 580 calories each day.”

Another recent survey of changing eating habits reports a similar increase in “eating occasions,” responsible for an increase of 39 daily average calories from 1977-78 to 2003-06. Lead researcher Barry Popkin, PhD, of the University of North Carolina-Chapel Hill commented, “In the US, snacking emerged gradually but really accelerated in the last 30 years.… Now you can buy snacks anyplace you go to buy anything.”

“We’ve been blindsided,” says Susan B. Roberts, PhD, director of Tufts’ HNRCA Energy Metabolism Laboratory and author of The “I” Diet www.instinctdiet.com. “People always loved calories, but opportunities to enjoy them have increased dramatically. Forty years ago, few people ate outside of mealtimes and regular snack times. And with the exception of an occasional ice-cream cone, almost no one ate while walking down the street. Nowadays, it’s hard to make a quick trip to the mall without encountering the enticing odor of a Cinnabon (730 calories per roll).”

The effects of this “snack attack” are felt at the cash register as well as in our waistlines. According to the Packaged Facts market-research firm, annual US packaged-snack sales hit $64 billion last year, up 14% from 2006, and are predicted to grow to $77 billion by 2015.

It’s no surprise, then, that a recent Harvard study pointed to potato chips as the number-one culprit in the nearly one pound a year that US adults gain as they age. About half the average 3.35 pounds a healthy, non-obese American gains over four years can be traced to potato chips, researchers found. The study looked at data on 120,877 participants in three long-running studies over 20 years. Sugar-sweetened beverages, a favorite liquid “snack,” were also major contributors, along with potatoes and red and processed meats.

Addicted to Snacks?
If snacks are so bad for us, why do we keep eating more of them? Another new study may suggest clues to the answer: Scientists reported that when laboratory rats were given foods high in fat, their digestive systems immediately began releasing natural chemicals similar to the active ingredient in marijuana. These chemicals, called endocannabinoids, caused the rats to crave still more fatty foods.

Daniele Piomelli, PhD, PharmD, of the University of California-Irvine, and colleagues sought to investigate the neural mechanisms underlying the body’s response to oral sensory signals. When given fat, the rats began producing the natural marijuanalike compounds as soon as the fatty liquid hit their taste buds. Only liquid diets high in fat, not those high in sugar or protein, produced the endocannabinoids.

“These findings provide a window on how we relate to fatty foods,” says Piomelli. “We have this evolutionary drive to recognize fat, and when we have access to it, to consume as much as we possibly can.”

The process starts on the tongue, he explains, where fats in food generate a signal that travels first to the brain and then through a nerve bundle called the vagus to the intestines. There, the signal stimulates the production of endocannabinoids, which initiate a surge in cell signaling that prompts the wanton intake of fatty foods, probably by initiating the release of digestive chemicals linked to hunger and satiety that compel us to eat more.

The addictive nature of snacks and other fatty foods is no surprise to David A. Kessler, MD, who served as commissioner of the US Food and Drug Administration (FDA) from 1990 to 1997. In his book, The End of Overeating, he explores how packaged foods and restaurant meals are crafted to be “hyperpalatable” by the layering of sugar, salt and fat (see our August 2009 Special Supplement). Such foods are engineered to trigger your brain to release dopamine, a neurotransmitter associated with the brain’s pleasure center—the same chemical connection that makes people crave alcohol or tobacco. Soon, your brain “lights up” with dopamine at even the thought of potato chips or Twinkies or Oreos.

“Once your working memory and thoughts are engaged by hyperpalatable food, you’re almost in a trance,” Dr. Kessler explains. The body’s dopamine and opioid responses to such foods combine with “cues” from the food and your associations with it to create a vicious circle of “conditioned overeating.”

He adds, “This is a very powerful human mechanism. It’s how we’re all wired, to focus on the most salient stimuli. Certain stimuli are inherently re-enforcing in an arousal-release phenomenon— don’t underestimate its power.”

Taking Charge
So what can you do to break this vicious circle and fend off those “snack attacks” that can derail your best intentions to eat healthier? Start by taking control of your eating. “When you eat only planned meals and snacks at planned times,” says Roberts, “your familiarity instinct stops prodding you with triggers that try to get you to eat at other times.” This basic human instinct wants structure, she explains, “and when it gets what it wants, it’s less inclined to encourage you to break the rules.”

Plan your grocery shopping, too. If you don’t keep unhealthy snacks in the house, you can’t lose control and gobble them up. Shop the perimeter of the grocery store, where most stores stock fresh produce and other from-scratch foods, and avoid the packaged-goods aisles.

Use the Nutrition Facts labels when you do venture in from the perimeter. Surprisingly, a recent Harris Interactive survey found that consumers are less likely to study nutritional information on “indulgence opportunities” such as crackers, cakes and candy. Apparently, consumers take a “what the heck” attitude toward treats: Only 54% check nutritional info on cakes, compared to 67% who use Nutrition Facts data to pick canned goods.

Be aware, however, that makers of sugary foods sometimes go to great lengths to downplay their products’ true “sugar rush.” In his book, Dr. Kessler notes that when a food contains more sugar than any other ingredient, federal regulations require that sugar be listed first on the label. But if a food contains several different kinds of sweeteners, they can be listed separately, which pushes each one farther down the list. Terms for sugars can include high fructose corn syrup, white sugar, brown sugar, corn syrup, corn syrup solids, raw sugar, malt syrup, maple syrup, pancake syrup, fructose sweetener, liquid fructose, honey, molasses, anhydrous dextrose and crystal dextrose.

Also scrutinize snacking options for calories and saturated and trans fat. Even healthy choices like nuts pack a surprising amount of calories, so snack on them in moderation. (A half-cup of mixed nuts, for instance, packs a surprising 400 calories.) Don’t obsess over the “total fat” number on nutrition labels, since that total includes healthy polyunsaturated fats, or the (dietary) cholesterol amounts. But do red-flag products high in saturated fat, which is the chief contributor to unhealthy blood cholesterol.

Sodium, despite a flurry of recent, seemingly contradictory studies (see page 1), remains an ingredient to limit— and an obvious problem with salty snacks. Salt can also turn otherwise healthy snacks like nuts and popcorn into nutritional negatives. (See box for a low-salt and butter-free alternative recipe for “movie-night popcorn.”) But sodium can lurk in almost any processed, packaged food: Two Twinkies snack cakes, for example, contain 440 milligrams of sodium, nearly 30% of what most experts advise as a daily maximum.

Movie Night Popcorn
If it’s not doused with butter and salt, popcorn is an ideal snack because it is high in fiber and low in calories. Nutritional yeast, not to be confused with brewer’s yeast or baker’s yeast, is the magic ingredient in this healthy topping alternative. Rich in B vitamins, it has a cheesy flavor and is sometimes used as a vegan substitute for Parmesan cheese. You can find it in the bulk section of natural foods stores.

Measure 1/3 cup popcorn kernels. Place 1 Tbsp olive oil and 5 of the popcorn kernels in heavy 3-quart saucepan. Heat over medium-high heat, holding lid slightly ajar to allow steam to escape and shaking pan occasionally, until the “test” kernels have popped. Add remaining popcorn kernels; stir to coat with oil. Cover pan, leaving lid slightly ajar, and heat, shaking pan often, until popping subsides. Remove from heat. Transfer popcorn to a large bowl. Add 1 Tbsp olive oil; toss to coat. Sprinkle with 2 Tbsp nutritional yeast and 3/4 tsp coarse sea salt (or kosher salt); toss to coat well. Yield: 6 (generous 1-cup) servings.

Per serving: Calories: 90. Total fat: 5 grams. Saturated fat: 0.5 grams. Cholesterol: 0 milligrams. Sodium: 240 milligrams. Carbohydrates: 10 grams: Fiber: 2 grams. Protein: 2 grams.

Tip: If you have a hot-air popcorn popper, you can use it to pop the corn without any oil. This reduces calories to 70 and total fat to 3 grams.

For two more healthy snacking ideas, see this month’s recipe card on page 6. And don’t forget that in-between-meal beverages count as “snacks,” too. In fact, half the calories contributed by snacks in that Purdue study came from beverages. Between 2006 and 2008, the study found, the time spent drinking beverages outside of meals jumped from 45 to 85 minutes a day. Roberts warns, “Liquid calories are sheer poison because they don’t make us feel as satisfied as solid calories and we end up having a drink on top of other things, not instead of them.”

Satisfying Substitutions
Clues to some smarter snacking selections come from that Harvard study that got headlines for implicating potato chips in the obesity epidemic. The researchers also looked at what foods were most associated with losingweight over a four-year period, per added serving per day. All five foods most linked to weight loss could also serve as snacks:

    • Yogurt (-0.82 pounds)
    • Nuts (-0.57 pounds)
    • Fruits (-0.49 pounds)
    • Whole grains (-0.37 pounds)
    • Vegetables (-0.22 pounds)

If those don’t fit your definition of “snacks,” maybe you need to redefine your between-meal thinking. Plain low-fat yogurt topped with berries can satisfy your sweet tooth while helping meet your daily calcium needs. Roast chickpeas for a crunchy treat, or turn them into hummus; use carrot or celery sticks instead of high-calorie crackers for dipping. “Apples make a portable, sweet-tasting snack,” Roberts suggests. “They’re low in calories, high in fiber, and hard to eat too quickly.”

Roberts actually recommends planning two snacks a day if you’re trying to lose weight, to control hunger. Healthy snacks can also be part of rituals with associations as positive as Thanksgiving turkey or Fourth of July barbecue. “Make a point of serving raw veggies with a low-fat yogurt dressing as a weekday snack before dinner,” she suggests, “or switch from pie to berries with a touch of lemon and sugar for a weekday treat.

“Serve these substitutions as often as you can when you eat with family and friends, and pretty soon you’ll begin to make the connection between these healthy foods and the comfort of a life in balance.”

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