October 2013 Issue

Snacking Benefits
By Densie Webb, PhD, RD
Today’s Dietitian
Vol. 15 No. 10 P. 44

Research suggests nutritious snacks that fit into your clients’ calorie needs may control weight and improve overall health.

When clients hear the word “snacking,” visions of double-stuffed cookies, caramel fudge ice cream, and you-can’t-eat-just-one chips likely come to mind.

While Americans tend to munch on too much of these unhealthful options, when snacking is done right, it can contribute to intakes of much-needed nutrients, help curb appetite, and possibly help control weight. However, according to a recent article in The New York Times, manufacturers of tasty, high-calorie snacks spend an enormous amount of time, energy, and money “to get people hooked on foods that are convenient and inexpensive.”

Are your patients’ and clients’ snacking habits contributing to poor diets and weight gain? Today’s Dietitian evaluates the current state of Americans’ snacking habits and what can be done to buck the growing trend toward increased intakes of salty, high-fat, high-calorie snacks and make snacking a healthful eating experience.

How We Snack
Americans are snacking more than ever. National Health and Nutrition Examination Survey (NHANES) data show that between 1977-1978 and 2007-2008, the percentage of adults who snacked increased from 59% to 90%. In 1977-1978, 73% of adults snacked only once daily or not at all. In 2007-2008, almost two-thirds of adults snacked two or more times daily, contributing an average of 24% of total daily calories (586 kcal for men and 421 kcal for women).1 According to a cross-sectional study of 4,259 obese men and women and 1,092 subjects used as a reference population, nearly one in six adults obtain more than 40% of their total daily calories from snacks.2 Overall, adults aged 60 and older consume fewer calories as snacks than younger groups.1

NHANES data also show that 83% of adolescents consume at least one snack on any given day.3 Snacking among children has increased dramatically over the past few decades as well.4 Children currently snack almost three times per day, providing more than 27% of their total daily calories, mostly as desserts and sweetened beverages.5

What’s more, in a systematic review, television watching likely contributes to excessive snacking, regardless of age.6 However, in adults, alcohol consumption is more likely than television to trigger “the munchies,” according to a meta-analysis.7

While children need the nutrition that healthful snacks provide, it’s unclear whether the shift to three meals and three snacks per day of questionable nutritional value can cause physiological effects such as changes in insulin and blood glucose levels that may contribute to health issues, including overweight and obesity.5

Nonetheless, the increase in snacking among all age groups raises a red flag about the effect it may have on health, especially on the growing epidemic of overweight and obesity, as nearly one-third of American children and adolescents and almost 70% of adults are either overweight or obese.8,9

Does Snacking Make You Fat?
Research suggests that men and women who are obese snack more frequently than normal-weight men and women.2 A study of elementary school children in the Philippines found that those who snacked the most were more than twice as likely to be overweight as those who consumed the fewest snacks.10 That only makes sense, given that the caloric density of common snack foods tends to be greater than that of foods eaten at meals.5

“I think eating frequency is a bigger problem than increased portion size,” says Richard Mattes, MPH, PhD, RD, a professor of nutrition at Purdue University. Moreover, he says people generally don’t compensate for their snacks by eating less at the next meal.11

But the type of snack food clearly makes a difference. According to Chris Ford, MPH, a doctoral candidate and researcher at the University of North Carolina at Chapel Hill, “Sugary beverages are one type of snack that often leads to excess caloric intake. Liquid calories are even more difficult to compensate for than other snacks.”

Additionally, as part of a study, children who ate snack foods higher on the satiety index in combination, such as vegetables and cheese, consumed up to 72% fewer calories before being satisfied than those who ate snack foods such as potato chips. This also enables them to consume a wider variety of nutrients than if they ate just the cheese or the vegetables.12

Ironically, frequently eating small meals is a popular foundation for weight-loss plans, based on the belief that this behavior increases metabolism, reduces hunger, and improves glucose and insulin control, all of which helps reduce body weight.13 Such claims are based on studies that show snacking helps with weight management. Some studies have shown that among adolescents, those who snack frequently were less likely to be overweight or obese and have abdominal obesity.14 Other studies have found that female adolescents who snack less frequently may experience greater weight gain over time than those who eat more frequently.15 An analysis of adolescents who participated in NHANES 2001-2004 found that each additional snack was associated with a 0.4 decrease in BMI.16 

While it’s difficult to reconcile the fact that snacks often contribute excess calories yet seem to be unrelated to overweight and obesity, there are two possible explanations. First, definitions for what makes an eating occasion a “snack” vary widely among studies, making it tough to accurately assess how much and how often snacks actually are eaten.17 Anything eaten in between meals, whether it’s carrot sticks, yogurt, or an apple, is sometimes considered a snack, whereas some studies count only traditional snack foods, such as chips, cookies, or crackers, as snacking. Still others consider those foods eaten at specific times during the day as snacks.5 In addition, underreporting of food intake is a well-recognized problem in dietary studies, making it a challenge to know whether there’s really a connection between snacking and weight.

Snacking and Appetite
A symposium on eating patterns and energy balance held in 2009 concluded that snacking has little, if any, effect on appetite control and food intake. However, some research shows there may be a small benefit to eating three meals and three snacks per day compared with eating three meals per day, and reducing eating frequency to fewer than three times per day seems to increase appetite.13,18 Other research suggests that snacking may help curb appetite, especially high-protein snacks, but the effect of a high-protein snack isn’t very strong.11

Nutrient Contribution of Snacks
While snacking often is thought of as adding little beyond calories, fat, and sugar, one study, using data from NHANES 1999-2004, found that snacking was associated with more nutrient-dense diets as measured by the USDA Healthy Eating Index-2005 scores.19 Other studies have demonstrated nutritional benefits of snacking, such as an improved intake of micronutrients and recommended food groups, especially among populations that are at nutritional risk.19,20

A study of postmenopausal women who were overweight or obese found snacking was associated with the consumption of more fruits, vegetables, and fiber-rich foods.21 The same is true of adolescents.1

An analysis of the Third NHANES found that snacking was related to greater intake of some nutrients, including folic acid, calcium, magnesium, iron, and potassium.20 “Snacking is a great opportunity to slip in missing food groups, especially fruits and vegetables,” says Jill Weisenberger, MS, RD, CDE, a private practitioner and the author of Diabetes Weight Loss — Week by Week.

While snacks provide between 7% and 38% of adults’ total daily intakes of MyPyramid food groups, they also provide at least 17% of the solid fats1 and as much as 42% of both natural and added sugars22 in the diets of children and adults. On the plus side, snacks contribute 22% of Americans’ daily intake of potassium, 21% of fiber, 25% of calcium, and 18% of vitamin D.22

Sodium from snacks also is a concern. NHANES data from 2009-2010 showed that snacks provide between 10% and 19% of sodium in the diet, depending on the age group, with adolescent girls obtaining the largest percentage of dietary sodium from snacks. Salty snacks represented the greatest increase in caloric intake between 1977 and 2006 among children aged 2 to 18.5

While regular snacking appears to help children and adolescents meet dietary recommendations, especially for young children, unhealthful snacking can contribute to excess energy intake and a decrease in nutrient density in their diets.

Health Effects of Snacking
Aside from studies on snacking and weight, not much research has examined the effects of snacking on disease risk factors. Two small controlled studies, one from Canada and one from Iran, found that nibbling or snacking resulted in lower levels of cholesterol, triglycerides, and low-density lipoproteins, and higher levels of high-density lipoproteins.23,24 However, the Canadian study compared three meals per day with 17 so-called smaller meals per day and included only seven men. In the Iranian study, none of the changes in cardiovascular disease risk factors were significant, though it was suggested that a nibbling meal pattern may have a beneficial effect on blood sugar and insulin levels.

An association between men’s snack consumption and an increased risk of type 2 diabetes was found in the Health Professionals Follow-Up Study, but the increased risk wasn’t significant after additional adjustment for BMI.25

Snacking Advice for Clients
The jury is still out on whether snacking, nibbling, or grazing is a healthier meal pattern than eating three meals per day and what effect snacking may have on weight. Clearly, the type of snack is at least as important as whether someone snacks at all. However, the foods and beverages that contribute the most calories as snacks in the American diet aren’t the most nutritious options.1 The full picture of the role snacks play in overweight and obesity and to what degree they contribute to nutrient intakes is unclear, most likely because of the methods used in studies. What’s clear is that if snacks are a regular part of your clients’ and patients’ eating patterns, they can benefit from learning ways to make the snacks they eat more nutritious and fit within their calorie needs.

As is often the case, the devil is in the dietary details. Mattes believes that the risk of gaining weight by snacking is low when snacks are part of a well-planned, energy-balanced diet. Patients and clients should understand that to eat healthfully, lose weight, or reduce risk of chronic diseases, such as cardiovascular disease and type 2 diabetes, they don’t have to give up snacking. As mentioned, some studies suggest that snacking can be beneficial to nutrient intakes and to health. However, undetailed advice to simply snack could lead to excess calorie intake and weight gain.

The goal is to make snacking a positive nutrition experience that helps meet dietary recommendations set by the 2010 Dietary Guidelines for Americans. In keeping with these requirements, the USDA recently issued new guidelines and educational materials for providing “smart snacks” in school (available at www.fns.usda.gov/cnd/governance/legislation/allfoods.htm). While the USDA is targeting foods provided in schools, the smart snacking tips can be applied to children and adults alike.

— Densie Webb, PhD, RD, is a freelance writer, editor, and industry consultant based in Austin, Texas.

 

Advice for Clients
Share these tips with clients and patients who make snacking part of their daily diet:

• Don’t add snacks, even healthful snacks, to your diet if you’re already meeting your daily calorie requirements.

• Plan and prepare nutritious snacks. Don’t engage in mindless snacking while watching television, for example, which can add excess calories. (For more information about mindless eating and ways to get it under control, visit www.mindlesseating.org).

• Choose high-protein snacks such as low-fat and fat-free yogurt, low-fat cottage cheese, reduced-fat cheese, nuts, and hard-boiled eggs. Protein leaves you more satisfied than carbohydrates or fats.

• Choose snacks from more than one food group (eg, carrot sticks and yogurt, apples and peanut butter, reduced-fat cheese and whole-grain crackers) rather than single-item snacks (eg, cheese, crackers, yogurt) to consume a wider variety of nutrients.

• Think outside the snack box and eat breakfast foods, such as cereal and skim milk or scrambled eggs and toast, or leftovers from dinner, including glazed carrots, vegetable stew, or lentil soup.

• Choose snacks that contribute to recommended food groups, such as low-fat and fat-free yogurt, whole grain breads and crackers, and fruits and vegetables.

• Create a snack choice list to keep from getting in a snacking rut.

— DW

 

References
1. Sebastian RS, Wilkinson Enns C, Goldman JD. Snacking Patterns of U.S. Adults: What We Eat in America, NHANES 2007-2008. Food Surveys Research Group Dietary Data Brief No. 4. June 2011. http://ars.usda.gov/SP2UserFiles/Place/12355000/pdf/DBrief/4_adult_snacking_0708.pdf

2. Bertéus Forslund H, Torgerson JS, Sjöström L, Lindroos AK. Snacking frequency in relation to energy intake and food choices in obese men and women compared to a reference population. Int J Obes (Lond). 2005;29(6):711-719.

3. Sebastian R, Goldman J, Wilkinson E. Snacking patterns of US adolescents: What We Eat In America, NHANES 2005–2006. Food Surveys Research Group Dietary Data Brief No 2. September 2010. http://ars.usda.gov/SP2UserFiles/Place/12355000/pdf/DBrief/2_adolescents_snacking_
0506.pdf

4. Larson N, Story M. A review of snacking patterns among children and adolescents: what are the implications of snacking for weight status? Child Obes. 2013;9(2):104-115.

5. Piernas C, Popkin BM. Trends in snacking among US children. Health Aff (Millwood). 2010;29(3):398–404.

6. Pearson N, Biddle SJ. Sedentary behavior and dietary intake in children, adolescents, and adults. A systematic review. Am J Prev Med. 2011;41(2):178-188.

7. Chapman CD, Benedict C, Brooks SJ, Schioth HB. Lifestyle determinants of the drive to eat: a meta-analysis. Am J Clin Nutr. 2012;96(3):492-497.

8. Ogden CL, Carroll MD, Kit BK, Flegal KM. Prevalence of obesity and trends in body mass index among US children and adolescents, 1999-2010. JAMA. 2012;307(5):483-490.

9. Obesity and overweight. Centers for Disease Control and Prevention website. http://www.cdc.gov/nchs/fastats/overwt.htm. Last updated May 30, 2013.

10. Gonzalez-Suarez CB, Lee-Pineda K, Caralipio ND, Grimmer-Somers K, Sibug EO, Velasco ZF. Is what Filipino children eat between meals associated with body mass index? Asia Pac J Public Health. 2013;Epub ahead of print.

11. Chapelot D. The role of snacking in energy balance: a biobehavioral approach. J Nutr. 2011;141(1):158-162.

12. Wansink B, Shimizu M, Brumberg A. Association of nutrient-dense snack combinations with calories and vegetable intake. Pediatrics. 2013;131(1):22-29.

13. Leidy HJ, Campbell WW. The effect of eating frequency on appetite control and food intake: brief synopsis of controlled feeding studies. J Nutr. 2011;141(1):154-157.

14. Keast DP, Nicklas TA, O’Neil CE. Snacking is associated with reduced risk of overweight and reduced abdominal obesity in adolescents: National Health and Nutrition Examination Survey (NHANES) 1999-2004. Am J Clin Nutr. 2010;92(12):428-435.

15. Ritchie LD. Less frequent eating predicts greater BMI and waist circumference in female adolescents. Am J Clin Nutr. 2012;95(2):290-296.

16. Sebastian RS, Cleveland LE, Goldman JD. Effect of snacking frequency on adolescents’ dietary intakes and meeting national recommendations. J Adolesc Health. 2008;42(5):503-511.

17. Johnson GH, Anderson GH. Snacking definitions: impact on interpretation of the literature and dietary recommendations. Crit Rev Food Sci Nutr. 2010;50(9):848-871.

18. McCrory MA, Campbell WW. Effects of eating frequency, snacking, and breakfast skipping on energy regulation: symposium overview. J Nutr. 2011;141(1):144-147.

19. Zizza CA, Xu B. Snacking is associated with overall diet quality among adults. J Acad Nutr Diet. 2012;112(2):291-296.

20. Kerver JM, Yang EJ, Obayashi S, Bianchi L, Song WO. Meal and snack patterns are associated with dietary intake of energy and nutrients in US adults. J Am Diet Assoc. 2006;106(1):46-53.

21. Kong A, Beresford SA, Alfano CM, et al. Associations between snacking and weight loss and nutrient intake among postmenopausal overweight to obese women in a dietary weight-loss intervention. J Am Diet Assoc. 2011;111(12):1898-1903.

22. Table 25: Snacks: percentages of selected nutrients contributed by foods eaten at snack occasions, by gender and age, in the United States, 2009-2010. In: Agricultural Research Service. What We Eat in America, NHANES 2009-2010. Washington, DC: US Department of Agriculture; 2012. http://www.ars.usda.gov/SP2UserFiles/Place/12355000/pdf/0910/Table_25_SNK_GEN_09.pdf

23. Rashidi MR, Mahboob S, Sattarivand R. Effects of nibbling and gorging on lipid profiles, blood glucose and insulin levels in healthy subjects. Saudi Med J. 2003;24(9):945-948.

24. Jenkins DJA, Khan A, Jenkins AL, et al. Effect of nibbling versus gorging on cardiovascular risk factors: serum uric acid and blood lipids. Metabolism. 1995:44:549-555.

25. Mekary RA, Giovannucci E, Willett WC, van Dam RM, Hu FB. Eating patterns and type 2 diabetes risk in men: breakfast omission, eating frequency, and snacking. Am J Clin Nutr. 2012;95(5):1182-1189.

The Evolution of Snacking

Adults


Years 

Meal Calories

Snack Calories

Total Calories

1977-78

1,569

196

1,765

1994-98

1,636

361

1,997

2003-06

1,692

472

2,164 

Children


Years 

Meal Calories

Snack Calories

Total Calories

1977-78

1,586

244 

1,830

1994-98

1,528

423

1,951

2003-06

1,524

496

2,020

— Source: Popkin BM, Duffey KJ. Does hunger and satiety drive eating anymore? Increasing eating occasions and decreasing time between eating occasions in the United States. Am J Clin Nutr. 2010;91(5):1342-1347.

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