Along-held belief is that calories are calories no matter if they hail from bacon or broccoli. Take in fewer calories than you burn and it’s your ticket to winning the battle of the bulge. It’s true that any calorie from a food supplies a set amount of energy, but once eaten, things become more complicated. A newer era of research is making it clear that perhaps not all calories are created equal. Read on to learn more about the complex calorie.
The macro effect
The true calorie count of a food may very well be different than what’s labeled due to its “thermic effect” (i.e. the energy required to digest and process it). The best example is protein, which has a higher thermic effect than carbs or fat so a lower percentage of its calories (4 calories per gram) will be available for storage in the body.
In a JAMA study, people who got 25 percent of their calories from protein burned 227 more calories a day than those who only ate 5 percent of their calories from protein. So even though 3 ounces of chicken breast may have 92 calories on paper, up to 35 percent fewer of those calories will actually be absorbed by the body. “…calories from protein have also been shown to have a greater impact on satiety, and hunger is the enemy of weight loss,” says New York weight loss expert Samantha Cassetty, M.S., R.D.
The carb math
A study in the American Journal of Clinical Nutrition showed that when people ate the same diet except for whole grains versus refined grains, those consuming items like brown rice and whole wheat bread burned almost 100 more calories per day than those who ate the refined versions. This was likely due to both a metabolic boost as well as extra calorie excretion.
“Your body has to work harder to digest a meal containing less processed carbs so will burn off more calories to do so,” notes Cassetty. In other words, 100 calories from quinoa are not the same as 100 sugary calories from soda in the weight loss equation.
A report in Obesity Reviews noted that calories from sugary drinks play a unique role in health problems and disease risk increases even when the beverages are consumed within calorie-controlled diets that do not result in weight gain.
Any degree of external processing— including cooking, grinding and juicing — ruptures cell walls in a food thereby lessening the energy needed for our bodies to digest it so we extract more of its calories. Raw or lightly cooked meat (i.e. sushi and rare steak) require extra internal processing to deal with more tightly wound muscle fibers and supply fewer usable calories than well-done meat. A study in the journal Obesity fed people the same number of calories as a liquid or solid and noted that post-meal hunger was greater after liquid calories. Overall, a solid meal leads to a greater drop in levels of the hunger-inducing hormone ghrelin, which could help trim overall calorie consumption.
Fascinating research shows that the amount of energy (calories) derived from nuts, such as almonds, walnuts and pistachios, after we eat them is up to 30 percent less than previously thought. Some of the calories in nuts are found within hard-to-digest cell walls and microbes in your gut get access to a handful of the nut calories as well so in the end we don’t absorb all their upfront calories. This is likely one reason why studies have failed to show that eating calorie-dense nuts leads to weight gain.
Quality over quantity
Here’s more evidence that you should look beyond calories when judging a food: In a trial published in the New England Journal of Medicine people whose diets included more servings of potato chips, potatoes, sweetened drinks, and red or processed meats gained more weight during four-year intervals while those who ate more vegetables, fruits, nuts, whole grains and yogurt were protected from creeping weight gain. “Some calories just work a lot harder for us than others, so if we’re focusing solely on calories alone we’re missing the big picture,” Cassetty says. In other words, 100 calories from candy are not the same as 100 calories from cauliflower.
Watch the clock
Eating calories at certain times of day may make them less … caloric. Data shows that consuming calories earlier in the day can lead to better weight management. “Our biological clocks impact how our bodies handle the calories it receives and it seems we are primed to deal with the biggest meal of the day in the morning,” explains Cassetty. So consider eating breakfast like a king and dinner like a pauper for a bigger calorie burn.
Boost your (calorie) burn: Make the calories you eat work harder for you.
—Protein burn: Take advantage of the extra calorie cost associated with digesting protein, by including this macronutrient at meals and snacks.
—Fiber up: It takes more effort to breakdown fiber-rich foods which means a greater calorie burn during digestion. So get chummy with high-fiber items like legumes and vegetables.
— Go nuts: Snack on whole nuts for a bounty of must-have nutrients.
— Be label savvy: Look beyond the calorie count and pay attention to the form of their ingredients. Whole blueberries are good, blueberry muffin mix not so much.
— Avoid the sweet stuff: Calorie for calorie, added sugars seem to be particularly efficient contributors to weight gain.
— Natural selection: Focus on eating more single ingredients foods like fish, whole seeds and kale which require your body to work harder to handle them, and in turn burn more calories.
— Solid state: Consume more of your daily calories from solid foods and less from liquids.
— Raw powder: Include more high-burning raw foods (like raw sunflower seeds and veggies) into your menu. Larger quantities of raw food require more laborious chewing which expends additional energy and also encourages satiety.
— Eat bugs: The bacteria in your gut may play a part in how you digest food and how many calories you derive from it. Keep your microbiome in calorie-burning shape by including a daily supply of fermented foods like yogurt and sauerkraut.
— Start early: Consider making your morning meal more substantial and then tapering down calorie intake as the day progresses.
Matthew Kadey, M.P.H., R.D.N.