Back in the 70s, liquid diets were “hot” —liquid meal replacements and diet shakes had just entered our lexicon. And today, liquids are hotter than ever, with the popularity of juicing, and new beverages, such as coffee and tea, sports and energy drinks, enriched waters, and smoothies. Some liquid supplements and juices may be an effective way to increase your daily nutrient intake, but studies indicate that consuming an increased volume of liquid calories may be counterproductive for health.
The sugar-sweetened beverage trap. It’s been documented that sugar-sweetened beverages, including sodas and artificially flavored “fruit” drinks—rich in calories through readily absorbable sugars—may contribute to chronic diseases. A 2010 study published in Diabetes Care found that regular consumption of sugar-sweetened beverages is associated with an increased risk for type 2 diabetes and weight gain.
Sodas and “fruit” drinks are well known culprits for added calories, but many other beverages, such as smoothies and sports drinks, also can add calories to your daily intake without contributing much to satiety. In fact, a 2008 review published in Obesity Reviews suggests that fluid calories are not recognized by the body in the same way solid foods are. Consuming liquid calories does little to suppress ghrelin—the body’s hunger-stimulating hormone—as effectively as consuming solid foods. This means you may feel hungry even after you’ve finished a high-calorie smoothie, juice, or milkshake. Typically, people don’t compensate for those extra calories from their beverage by reducing their intake of food, resulting in more calories consumed. This was the case in the Nurses’ Health Study, which followed over 50,000 women for eight years. The study found that women who reduced their intake of sugar-sweetened beverages cut their daily caloric intake by an average of 319 calories. Other female participants who increased their intake of such beverages from one per week to one or more per day ended up consuming an extra 358 calories each day.
Your best bet is to steer clear of liquid calories and stick to water and other zero-calorie beverages, such as plain coffee or tea. It may be a better idea to focus on solid foods, such as whole fruit, over their liquid, juice form. You’ll end up more satisfied and less likely to overeat throughout the day.