A Calories is NOT a Calorie

It sends us reeling when clients will report an off plan, highly processed packaged food with the caveat "oh but it was only XXX calories".  Those of us who grew up in the 80s and 90s fondly remember obsessively counting calories, looking for low fat diet foods like they were the holy grail of health before heading to do our Cindy Crawford workout video. Did it work?  Well, somewhat. 

Yes, if you've been eating in an energy surplus and then reduce your intake, you likely will lose some weight. If there isn't enough fuel beig put into your body, it will obviously need to dip in to your energy reserves- or stored fat.

That said, the biggest misconception is that "a calorie is a calorie", when nothing could be further from the truth.  The way your body processes calories and stores them is different.  The type of food, time it is consumed and quantity all influence whether food is used to fuel your body, or is stored as fat.

Type of Food
The Thermic Effect of Food or TEF is the calories used by the body to break down food.  TEF is different for different types of food.  The TEF of fat is 0–3%, Carbohydrate is 5–10%, and protein TEF is 20–30%; meaning your body burns off 20-30% of the protein you eat just in processing it. Simply put, it requires very little energy for your body to process fat and carbohydrates, and more to process protein. 

Beyond caloric burn, other critical metabolic metrics are greatly affected by type of food!  A study of adults with type 2 diabetes compared a paleo diet (gluten free, dairy free and grain free) to a diet based on the American Diabetes Association recommendations. All food was provided to the participants by the research staff and the diets were completely identical from a macronutrient (calorie) standpoint. The only difference was the type of carbohydrate (starchy vegetables and fruits instead of cereal grains). The Paleo diet led to superior improvements in nearly every outcome of interest, including insulin sensitivity, glycemic control, and blood lipids. In short, a calorie isn't just a calorie, nor is a carbohydrate just a carbohydrate!

Fiber Matters

Fiber content of food inhibits the absorption of calories- which is why a 50-calorie cookie vs a 50-calorie apple (also a carbohydrate) is more apt to be stored as fat.  Packaged foods and snacks tend to be lower in fiber than fruits and vegetables, thus more of their calories are absorbed by the body.  Beyond higher fiber, fresh fruits and vegetables also have higher water content, making them more filling!

Meal Timing

A study published in the American Journal of Clinical Nutrition discovered that the Thermic Effect of Feeding is higher in the morning than at night.  Volunteers were given identical meals of about 500 calories at three different times. In subjects who ate at 9 am, TEF increased by 16%; in subjects who ate at 5 pm, TEF increased by 13.5%; and in those fed at 1 am, TEF increased by only 11%. So it’s clear that we burn more calories in the morning For this reason it is better to have lighter meals in the evening, when TEF is lowest.

Meal Size

Calories are more likely to be stored as fat and less likely to be used immediately for energy or used to build new muscle when they are consumed in excess your body's current need; simply put, large meals are more likely to be stored. This is why six small meals totaling 2,500 calories are not equal to two large meals totaling 2,500.  This is why we always tell clients not to "double up" when eating if they've missed a meal. 

Difficult to Estimate

Studies show people tend to under-report/estimate what they eat and dramatically overestimate their caloric burn.  Fitness trackers like Apple Watch are off by an average of 24.3%.  Second,the FDA allows for a 20% margin of error in labeling calorie content, so it is extraordinarily difficult to estimate calorie consumption outside of a lab setting.  So even if all calories were equal, it is next to impossible to accurately assess your intake. 

So ditch the trackers and food logs and rely of a clean diet of whole, unprocessed foods that are high in nutritional value, filling and delicious!