Although the increased incidence of obese and overweight children and adolescents1 observed since 1984 seems to have stabilized at 11% and 32% between 1999 and 2006, the lifelong impact of obesity on health, economics, and quality of life is an important public health issue. In her review, Allman-Farinelli2 concludes that public health policy should be structured to reduce sugar-sweetened soft drink (soda) consumption to address global obesity and associated increased risk of developing metabolic syndrome and type 2 diabetes mellitus.

Energy consumption is unarguably important in achieving energy balance and maintaining a healthy body weight. However, is there significant scientific agreement to establish a public policy targeting soda consumption to address obesity? Or does the science support a public health approach whereby guidance should address calories from all liquid sources, that is, all beverages?

There is a substantial body of evidence that human beings do not compensate when eating for calories consumed in liquid form.3,4 Long-term interventions (10 weeks) show that habitual consumption of caloric beverages leads to significantly increased daily energy intake, weight gain, and body mass index in adults when compared with those consuming noncaloric beverages.5,6 Rolls et al7 reported that lunch meal calories were not affected by the ingestion of 8 or 16 oz of lemonade with or before (30 or 60 minutes) lunch. However, total energy intakes were significantly greater when the 42 participants drank sucrose-sweetened lemonade (vs aspartame-sweetened lemonade, water, or no beverage). In a similar study, DellaValle et al8 offered 48 women a test lunch without a beverage (control) or with a beverage consisting of 360 g of water, diet soda, regular (caloric) soda, orange juice, or 1% fat milk. Lunch meal energy intake was nonsignificantly lower when caloric beverages (regular soda, juice, and milk) were consumed, and total energy intake was significantly increased when compared with no-beverage, diet soda, and water treatments.8 Although food intake (kilocalories) at a test meal was unaffected by beverage portion size or energy content, more total calories were consumed when drinking regular soda (caloric) than diet soda or water.9 Mourao et al10 conducted a crossover challenge study in 120 adults where beverages and solid foods were matched for macronutrient content and calories. They found that the inclusion of a caloric beverage in a lunch meal led to greater daily energy intake compared with customary intake or days when a solid food with similar macronutrient and caloric content was ingested. Monsivais et al11 had 37 adults consume isocaloric soda beverages sweetened with sucrose, high-fructose corn syrup with 42% or 55% fructose, 1% fat milk, diet soda, or no beverage 2 hours after a standard breakfast and 2 hours before a cafeteria lunch. Pairwise comparisons showed that the 3 sugar conditions did not differ from each other or the milk; however, all 4 caloric beverages differed significantly from the diet soda and no-beverage conditions.11 A meta-analysis of randomized control trials found a significant reduction in total energy intake (15%) when aspartame-sweetened soft drinks were compared with nonsucrose controls such as water.12 Murphy et al13 reported that mean energy intakes by milk consumers were significantly greater than energy intakes by milk nondrinkers for all groups of children except boys aged 6 to 11 years. Moreover, more than 50% of flavored milk drinkers aged 2 to 5 years consumed whole milk rather than reduced-fat flavored milk.13 Flavored milks have been suggested as a means to positively affect calcium, phosphorus, and fiber intakes by replacing soda and fruit drink consumption without increasing added sugar intakes.14 However, this study showed that children consuming more than 240 g of flavored milk per day consumed more milk, soft drink, fruit juice, and fruit drink and, therefore, more liquid calories than did nonconsumers of milk. Females 12 to 19 years who consumed soda (regular and diet) and milk had the highest average energy intakes (1,982 +/- 62 kcal/d), whereas those who do not drink milk and soda had the lowest energy intakes (1,593 +/- 92 kcal/d).15 From these studies, it can be concluded that people do not accurately compensate food energy intake for beverage calories. Second, if the goal is to reduce weight gain, it is important to distinguish between caloric and noncaloric beverages when providing dietary guidance.

Nutrition guidance was simpler when policy could focus on emphasizing nutrient density in the context of energy balance. However, because of the increasing incidence of obesity, the 2005 Dietary Guidelines for Americans16 has 2 messages: (1) "consume fewer calories, be more active" and (2) "make wiser choices within and among food groups." Rather than targeting soft drinks to address obesity, the science supports a recommendation to choose lower energy choices within the entire consumer-packaged beverage group. Just as with other food groups, people should be encouraged to consume fewer liquid calories as consumer-packaged beverages, that is, calorically sweetened (regular) carbonated sodas, cordials, "energy" drinks, "sports" drinks, sugar-sweetened iced teas, fruitades, fruit juices, fruit punches, "specialized" coffees, and dairy-based beverages. After all, from an energy balance perspective, an 8-oz glass of juice or regular soft drink containing 70 to 90 kcal is not the lowest energy choice, nor the highest (Table 1). Fortunately, advances in food science have generated many lower calorie and often nutrient-dense food and beverage options. Classically defined food groups are no longer the sole or often primary source of essential nutrients.17 Because of the lifelong impact of weight gain and associated chronic diseases, especially among children, dietary guidance needs to first focus on energy balance. Given the overriding issue of obesity, guidance to address nutrient inadequacies, that is, calcium, should guide individuals to lower calorie choices, especially when it comes to liquid calories, which seem to be invisible but are not once ingested.

Table 1. Comparison of the Nutrient Composition (per 8 fl oz) of Different Beverages

In summary, to address obesity and the contribution from beverages, people might be encouraged to follow these recommendations:

1. Control calorie intake to manage body weight. Choosing calorie-free or lower calorie beverages, that is, "diet" options, may reduce total daily energy intake.

2. Drink fluids to maintain normal hydration and avoid beverages that provide calories. If you drink caloric beverages, do so in moderation.

3. Engage in regular physical activity and reduce sedentary activities to promote health, well-being, and a healthy body weight.

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