A calorie is a calorie is a calorie
The saying, “A calorie is a calorie is a calorie” attempts to make the point that all calories are the same. While it’s true calories provide the same amount of energy regardless of source, there is a difference between how various foods affect overall health, satiety, and body weight.
Calories, The Same and Different
A calorie is defined as, “…the heat energy required to raise the temperature of one gram of water by one degree Celsius1.” In this sense, all calories are the same. A calorie from a “healthy” salad provides the same amount of energy as a calorie from an “unhealthy” soda. While the amount of calories are identical, the effects on health are not.
Research: Liquid vs Solid Calories for Weight Loss
Study 1. This study looked at the effects of various liquid calories on weight loss. Liquid calories were split into different categories: 1) sugar sweetened beverages (soda, fruit drinks), 2) diet drinks, 3) milk, 4) 100% fruit juice. Researchers concluded reducing intake of sugar sweetened beverages contributed to a much larger effect on weight loss than other liquid calories2.
The study found a reduction of one serving of sugar sweetened beverages per day resulted in 1.4 pounds lost at the 18 month mark. It found that a reduction of other liquid calories (diet drinks, milk, 100% fruit juice) only resulted in a loss of 0.53 pounds at the 18 month mark. Furthermore, researchers concluded a reduction of liquid calories was associated with a stronger effect on weight loss than a reduction in solid calorie intake2.
Study 2. The second study looked into the effects of liquid and solid carbohydrate intake on body weight. Subjects were given 450 calories of either soda or jelly beans on a daily basis for four weeks. Researchers concluded subjects had a lower overall energy intake during periods of solid intake (jelly beans) when compared to liquid intake (soda)3.
Study 3. This study looked into the effects of liquid and solid meal replacement products on overall food intake later in the day. Each subject was given either a meal replacement drink or solid bar. Two hours after their meal replacement, subjects ate oatmeal to a comfortable level of fullness. On average, the group on the liquid meal replacement ate 13.4% more oatmeal than those who had the solid meal replacement4.
What does all this research mean?
The studies indicate liquid calories are more dangerous in terms of unwanted weight gain than calories from solid food. Subjects on solid food fared better even when the solid option wasn’t great (jelly beans).
The research indicates solid calories do a better job increasing satiety and lowering overall [daily] calorie consumption. Research shows different types of calories determine how easy or difficult reaching a calorie deficient state is.
The Bottom Line
Before you run out and buy a five pound bag of jelly beans, creating a calorie deficit remains the only way to lose weight; jelly beans won’t help. Calories are still all the same, however, they don’t all lead to the same outcomes. The studies above highlight how making healthier choices leads to easier weight loss. Simple steps such as eliminating sugary beverages or choosing solid meals move you in the right direction.
- Conn, C. A., & Kravitz, L. (n.d.). The Remarkable Calorie.
- Chen, L., & Appel, L. J. (2009). Reduction in consumption of sugar-sweetened beverages is associated with weight loss: the PREMIER trial. The American Journal of Clinical Nutrition,89(5), 1299-1306. doi:10.3945/ajcn.2008.27240
- Dimeglio, D., & Mattes, R. (2000). Liquid versus solid carbohydrate: effects on food intake and body weight. International Journal of Obesity, 24(6), 794-800. doi:10.1038/sj.ijo.0801229
- Stull, A. J., & Apolzan, J. W. (2008). Liquid and Solid Meal Replacement Products Differentially Affect Postprandial Appetite and Food Intake in Older Adults. Journal of the American Dietetic Association, 108(7), 1226-1230. doi:10.1016/j.jada.2008.04.014