Snacking is much vilified in an age of epidemic obesity, and to some extent rightly so. The appellation "junk food" has come to be all but synonymous with "snack foods." With regard to many of the popular options, it is clear they are both snacks and junk—and rather less clear that they are food. I am pretty sure I have seen some of them glow in the dark.
As I have noted on prior occasions, food is the one and only construction material for the growing body of a child. Nutrients, extracted from foods, are used to build cells and tissues, hormones and enzymes. As with a house, or car, or coat, or shoe, the quality, durability, and tolerances of the final product are ultimately determined by the quality of the construction materials. Bad building material produces bad buildings—weak, and prone to untimely failures.
Is the application of such considerations to the growing body of a child you love in any way cute, or fun, or defensibly harmless?
Clearly not, and the costs of the blind eye we have collectively turned to this matter are all around us. Dollars, though numerous, are the least compelling measure of these costs. The more compelling measures are the life being sapped from our children's years, and the years possibly being siphoned from our children's lives. The measures include weight and body-mass index far above healthy thresholds.
Which brings us back to snacking. A voluminous scientific literature impugns the snack as part of the problem of epidemic obesity in adults, and particularly in children. None has contributed more decisively to this evidence base than Barry Popkin, Distinguished Professor of Global Nutrition at the University of North Carolina at Chapel Hill.
Now, it matters that snacking has been indicted by no less an authority than Prof. Popkin; he is on everybody's short list of preeminent nutrition and obesity experts in the world, certainly including mine. In fact, when I grow up, I want to be Barry Popkin.
But, there is a perhaps comparably august opposing voice. My mother. And probably yours, too.
When we were growing up, our mothers told us routinely not to snack. But, if your recollection of those exchanges is at all like mine, you will note that Mom did not say: "Don't snack or you'll get fat, acquire adult-onset diabetes in childhood, and possibly shorten your life expectancy."
No, Mom said nothing of the sort. Mom said, in fact: "Don't snack, because it will spoil your appetite."
Mom's concern, back in the day, was that if we ate between meals, we would eat less at meals. And since, back in the day, Mom had gone to the trouble of preparing those meals, she wanted our attention to them at meal time!
But if Mom was right—if snacking has the potential to "spoil," or reduce appetite—then how can snacking lead to an increase in calories, as Prof. Popkin and others suggest?
It depends entirely on the snack.
I have been thinking this way for a while. As I watched the literature on snacking accumulate, and evidence mount for its role in the obesity epidemic, I also recalled my own mother's position on the topic—and thought that perhaps Mom had been on to something.
To put nutritious food at my own fingertips, and keep my own appetite in check, I have used well-chosen snacks in a snack pack that is simply part of my daily wardrobe. I have done this for years, and it has always served me well. I have relied on the same strategy with patients, where it has had the same beneficial effects, while eliminating the psychological stresses associated with calorie control by avoiding food.
As a father of five, I have also long recognized the tendency of kids to want food when it's least convenient for parents to give it to them, and vice versa. So my wife and I took the approach of "if you can't beat 'em, join 'em." I built a "goody cupboard," designed to be at kid eye level, and my wife kept it full over the years (as it is to this day) with nutritious snacks within easy reach: nuts, seeds, dried fruits, whole-grain crackers, wholesome snack bars, etc. In addition, we always kept inviting and accessible bowls of fresh fruit on the kitchen counter, with some comparably wholesome choices, such as organic yogurts, in the fridge.
The idea, really, was Mom's: Snacking between meals might very well "spoil" appetite. So for that to be OK, we simply needed to make sure that all of the snacks on hand were filling and as nutritious as the meal-time foods they might be displacing. As a result, our kids should have wound up healthy and lean, with good quality diets, and a relaxed attitude about food because they were comfortable with the notion that they could eat when hungry.
And, I'm pleased to say, and meaning no disrespect to Prof. Popkin, it turned out exactly that way.
So, the next logical step was to do some research in this area. For the purpose, we made use of the increasingly ubiquitous KIND bars—a staple in the Katz household and a product made mostly of nuts and fruits—and committed to use of recognizable and pronounceable ingredients. In a study of nearly 100 overweight adults, we added two KIND bars daily to habitual diets for an 8-week period. Our findings, published in the Journal of Human Nutrition and Dietetics, included a potential improvement in diet quality, and no weight gain! This, despite the fact that we had added over 300 calories per day, and left our participants to their own devices to make room for those calories.
Apparently, they did exactly that. By adding calories in the form of a nutrient-dense and satiating food, snacking had apparently done just what Mom foresaw—reduced appetite at other times during the day.
There is now a growing body of evidence that wholesome foods can have this effect, even if they are quite energy dense. Nuts are high in calories, but they seem to confer a lasting feeling of fullness and, as a result, have potential to add valuable nutrients to the diet while helping to control appetite. The same appears to be true of dried fruits, and products made from them.
And so, we have several snacking studies now running in my lab. I'm pretty well convinced that snacking on the right foods can improve diet, health, and weight. But as a scientist, I am not inclined simply to trust such convictions; they need to be verified with good research, and that's our plan.
Nor are we the only ones on the job. In a paper just published in Pediatrics, food psychology expert Brian Wansink and colleagues demonstrated that overweight children filled up on fewer calories—while adding valuable nutrients to their diets—when given a wholesome snack choice as opposed to potato chips.
With regard to those chips, it's important to note that not all chips are created equal. Some are quite oily and salty, and even have added sugar. Others are products made from organic whole grains, healthful oil in moderate quantities, and a rather low concentration of added salt. The opportunities for healthful snacking may, to some extent, suggest choices between traditional snack foods of the variety indicted by Prof. Popkin (e.g., popular chips, dessert items, and sodas) and wholesome foods such as nuts, seeds, fruits, and vegetables; but they may also pertain to trading up within categories. My involvement in developing a measure of overall nutritional quality applied to over 100,000 foods reveals an impressive range of nutritional quality within most categories, including such items as salty snacks and even desserts.
And so we come back to Mom versus Prof. Popkin. Who is right? I think the matter can be resolved, with the help of William Shakespeare.
The Bard famously told us, "That which we call a rose, by any other name, would smell as sweet." That which we call a snack, however, implies a wide array of nutritionally disparate choices. They do not by any means all come comparably sweet—or salty, for that matter.
Both Prof. Popkin and Mom are right. It depends entirely on the nature of our snacking.
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David L. Katz, MD, MPH, FACPM, FACP, is a specialist in internal medicine and preventive medicine, with particular expertise in nutrition, weight management, and chronic-disease prevention. He is the founding director of Yale University's Prevention Research Center, and principal inventor of the NuVal nutrition guidance system. Katz was named editor-in-chief of Childhood Obesity in 2011, and is president-elect of the American College of Lifestyle Medicine.