Sodas, Soup, and Tea: The Effect of Liquids on Caloric Intake and Metabolism
July 1, 2001
Sodas, Soup, and Tea: The Effect of Liquids on Caloric Intake and Metabolism
July 2001; Volume 3; 49-51
By Adriane Fugh-Berman, MD
Many North Americans are struggling to control their weight. Several recent studies suggest that eliminating liquid calories may be a simple way to cut total caloric intake. Apparently, one must chew calories to trigger satiety signals, so liquid calories simply add to the day’s energy intake without affecting food intake.
Even highly caloric drinks taken before or with meals do not cause people to eat less food. A crossover study in eight women and seven men tested the effect of 1,880 kJ/d carbohydrate loads as liquid (soda) or solid (jelly beans), each given for four weeks with a four-week washout period between phases.1 Diet records were obtained at baseline and on random days throughout the study; body composition was measured weekly; and physical activity was assessed before and after treatments. Physical activity and hunger were unchanged. During the jelly bean phase, subjects adjusted their food intake to compensate for the extra calories. In contrast, subjects did not decrease their caloric intake during the soda period. Not surprisingly, body weight and body mass index (BMI) increased significantly only during the liquid period.
A study of 42 men compared the effects of several liquids given before or with meals on caloric intake. Subjects received no drink, water (8 or 16 oz), or lemonade (8 or 16 oz sweetened with either aspartame or sucrose).2 Drinks were given 30 or 60 min before lunch or with lunch. None of the liquids decreased food intake, so all caloric drinks increased total energy intake.
Soft Drinks and Weight Gain
Juice and milk supply nutrients along with calories; the same cannot be said for soft drinks, which are far more popular. In 2000, Americans bought more than 15 billion gallons of soft drinks. More than half of eight-year-olds drink soft drinks every day.3 Children and adolescents are especially big customers and have easy access: 60% of all middle and high schools sell soft drinks, and some schools even provide them free with purchased meals.3
| Table 1: Calorie content in popular beverages | ||
| Beverage | Serving Size | Calories |
| Water | 0 | |
| Diet cola | 20 oz | 5 |
| Coffee (with 1 liquid creamer) |
8 oz | 30 |
| Tea (with 2 packets sugar) |
8 oz | 50 |
| V8 | 11.5 oz | 70 |
| Fat-free milk | 8 oz | 90 |
| 1% milk | 8 oz | 100 |
| Apple juice | 8 oz | 110 |
| Cranberry juice | 8 oz | 140 |
| Ginger ale | 20 oz | 200 |
| Starbucks cappuccino | 20 oz | 200 |
| Ultra Slim-Fast | 11 oz | 220 |
| Arizona iced tea | 20 oz | 230 |
| Snapple lemonade | 16 oz | 240 |
| Sunny Delight | 20 oz | 300 |
| Odwalla future shake Vanilla A’lmondo |
16 oz | 380 |
| McDonald’s Coke (super size) |
42 oz | 410 |
| Baskin-Robbins chocolate shake |
24 oz | 1,130 |
| Adapted from: Center for Science in the Public Interest. Drink to me only. Nutr Action Healthletter 2000;November:9. | ||
Sugar-sweetened drinks may be a significant factor in childhood weight gain; a prospective 19-month study of 548 ethnically diverse school children in Massachusetts found that frequency of obesity and BMI both increased significantly with sugar-sweetened drink consumption. Each additional serving increased frequency of obesity (odds ratio 1.60; 95% confidence interval [CI] 1.14-2.24; P = 0.02) and BMI (mean 0.24 kg/m2, 95% CI 0.1-0.39, P = 0.03). The researchers adjusted for demographic, dietary, and lifestyle variables, and anthropometric measurements. Consumption of sugar-sweetened drinks at baseline also was significantly associated with increased BMI (mean 0.18 kg/m2 for each daily serving; 95% CI 0.09-0.27; P = 0.02).4
The Center for Science in the Public Interest (CSPI), a consumer advocacy group, notes that drink sizes have gotten larger and larger over the years, so a drink meant for an individual today is bigger than some family-size drinks in the 1950s.5 Some movie theaters serve 44-oz drinks; a 42-oz drink is available at McDonald’s; and the largest size drink at a 7-11 convenience store is 64 oz (eight cups).
Soup
While caloric drinks add calories without dimming appetite, a soup appetizer does decrease food intake. A controlled study of 24 lean women tested the effect of a premeal of chicken rice casserole (with or without a glass of water) vs. chicken rice soup on intake of calories at lunch. The casserole and soup contained the same ingredients, but were different in volume, form, and appearance. Compared to chicken rice casserole, eating soup significantly increased fullness, decreased hunger, and decreased caloric intake at lunch. Drinking a glass of water with the casserole did not affect satiety. The number of calories eaten at lunch was 1,209 (± 1 kJ) after the soup; 1,657 ± 148 kJ after the casserole with a glass of water, and 1,639 ± 148 kJ after the casserole without water. The reduced caloric intake at lunch did not cause the women to eat more at dinner. Other studies have also found that soup decreased subsequent intake. One study compared vegetable soup (blended or chunky) with vegetables (eaten with a glass of water) and found that soup decreased subsequent intake more than vegetables with water; the chunky soup was more effective than the blended soup.6 Another study found that tomato soup decreased subsequent intake more than melon or cheese and crackers.7
CSPI suggests that those watching their weight order small sizes of drinks, share beverages, put lots of ice in drinks, or consume low-calorie beverages (water, tea, coffee, or diet soda).
Tea
Tea may be particularly beneficial to the weight-conscious; a crossover study in 10 healthy men compared green tea extract (50 mg caffeine and 90 mg epigallocatechin gallate), caffeine (50 mg), or placebo given with meals, and found that ingestion of green tea extract increased thermogenesis, significantly increasing 24-hr energy expenditure (EE) (4%, P < 0.01) and decreasing 24-hr respiratory quotient (RQ) (from 0.88 to 0.85, P < 0.001) without changing urinary nitrogen.8 Norepinephrine excretion was 40% higher during treatment with green tea than with placebo (P < 0.05). The effect was not due solely to caffeine (known to be thermogenic); the caffeine control had no effect on EE, RQ, urinary nitrogen, or urinary catecholamines. Catechins in tea are thought to inhibit COMT, the enzyme that degrades norepinephrine, which helps to control thermogenesis and fat oxidation. Capsaicin (the compound that provides the heat in chili peppers) also has been shown to stimulate thermogenesis and fat oxidation in humans.
Given the drastic measures people are willing to take to lose weight, jettisoning caloric drinks, eating soup before meals, drinking tea, and eating spicy food seem like benign dietary modifications.
References
1. DiMeglio DP, Mattes RD. Liquid versus solid carbohydrate: Effects on food intake and body weight. Int J Obes Relat Metab Disord 2000;24:794-800.
2. Rolls BJ, et al. Effects of drinks sweetened with sucrose or aspartame on hunger, thirst and food intake in men. Physiol Behav 1990;48:19-26.
3. Squires S. Soft drinks, hard facts. Washington Post Health Magazine. February 27, 2001:10-15.
4. Ludwig DS, et al. Relation between consumption of sugar-sweetened drinks and childhood obesity: A prospective, observational analysis. Lancet 2001;357: 505-508.
5. Center for Science in the Public Interest. In the drink: When it comes to calories, solid is better than liquid. Nutrition Action Healthletter 2000;November:7-9.
6. Himaya A, Louis-Sylvestre J. The effect of soup on satiation. Appetite 1998;30:199-210.
7. Rolls BJ, et al. Water incorporated into a food but not served with the food decreases energy intake in lean women. Am J Clin Nutr 1999;70:448-455.
8. Dulloo AG, et al. Efficacy of a green tea extract rich in catechin polyphenols and caffeine in increasing 24-h energy expenditure and fat oxidation in humans. Am J Clin Nutr 1999;70:1040-1045.
July 2001; Volume 3; 49-51
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