A Deeper Look at “Calories In, Calories Out”

I’ve recently been thinking about these fragments in November that amalgamate to form that “Holiday Feel.” Some pieces are obvious such as the green, red, and white Wal-Mart merchandise or the talk of upcoming travel plans to visit family. The interesting ingredients are more subtle, individualized, and harder to define. With November comes cold mornings, the smell of a pellet stove, low-lying clouds along the Sandias, and the Sun taking an early exit across the Southern sky. For me, these signs of seasonal change herald in both an exciting and challenging time of year.

Eastern clouds rolling over the Sandias. Albuquerque, NM

With the Holiday landscape before us, I think this would be a good time to address some of those challenges from a nutrition perspective. Now, I believe that you should in no way deprive yourself of a satisfying dinner with the family full of heated political discourse. I do hope that after reading this, you’ll be more inclined to choose higher quality food from the table throughout the Holidays and beyond.

So lets talk about food quality. Why does quality matter? Both a cupcake and 3 eggs contain about 200 Calories, so why not just eat the cupcake if it tastes better? You may have heard the saying, “Calories in, Calories out.” As long as you burn more Calories than you eat, you’ll lose weight, so why should the type of food matter as long as you hit the right numbers?

As you can guess, my opinion is that food quality does matter. “Calories in, Calories out” is a true statement. If you eat fewer Calories than you burn, you enter a Caloric deficit and you will lose body mass. Food quality is important because it effects how easily you can enter a Caloric deficit. Sugary foods, or foods high in the Glycemic Index (I’ll explain) can seriously disrupt your hormones. These hormone changes cause your body to store more body fat, slow your metabolism, and feel hungrier. All of these combine to make a Caloric deficit very difficult to achieve.

The importance of food quality in achieving a Caloric deficit is outlined in the Carbohydrate-Insulin Model or CIM. To briefly summarize, sugary foods (high Glycemic Index) causes the body to produce large amounts of a hormone called insulin. This spike in insulin tells the body to immediately store your food as fat. Additionally, current fat stores are “locked in place.” Since the body’s fuel is now placed in storage, there is less available energy to actually use. This creates a state of perceived starvation, signaling an increase in hunger and a decrease in metabolism. As an overall effect, sugary foods cause both an increase in body fat storage while making it harder to enter a calorie deficit.

Next, I think its important to clarify what high Glycemic Index means. The Glycemic Index is a number assigned to a food that describes how quickly the food delivers sugar to your body. Foods assigned a number higher than 55 generally deliver sugar very quickly. This number does not describe the total amount of sugar in a food, rather, how quickly that sugar is absorbed into the body.

Glycemic Index (GI) is important because foods that contain both a high amount of sugar and a high GI will cause the pancreas (an organ near the liver) to produce large amounts of insulin. If we are consistently eating high GI and high sugar foods throughout the day, insulin stays elevated. This creates a situation where we are continuously storing fat and unable to use that energy, making us hungry, tired, and inclined to eat more.

Calories in, Calories out is indeed true, but our food choices can make a Calorie deficit either easier or harder to achieve. High sugar, high GI foods cause us to burn less energy, eat more, and immediately store energy as body fat.

Now, I want to discuss how we can use this information when choosing what to eat. First, its important to become aware of the GI value of different foods. A simple search online: “food name glycemic index,” will usually provide a number. After spending time searching for some common foods, you may be surprised to see high GI values for foods generally considered healthy. For example, carrots have a GI value of 71.

It’s important to remember that the total amount of carbohydrate in a food is also an important factor. Glycemic Load (GL) accounts for both the amount of carbohydrate and how quickly that carbohydrate is absorbed. For GL, you simply multiply the total amount of carbohydrate by the glycemic index and divide by 100. So, for a carrot:

1 carrot has 8 grams of carbohydrate and a GI of 71

GL = 8g x 71/100 = 5.7

A GL of 10 or less is low, 11-19 is medium, and 20+ is high. As you can see, although a carrot delivers sugar quickly to the body, there is not enough sugar to greatly effect insulin.

I recommend that you take a look at the GL value for the foods that you commonly eat. Personally, I believe that a diet of leafy greens, fruits, nuts, and meat will reduce the likelihood of consistently elevated insulin. Occasional fasting will also do wonders at lowering insulin although that’s a discussion for another time.

So here’s my advice for the holidays. I want you to remember that our daily habits shape who we are. If we eat high carb, high GI foods every day, it will manifest itself in our health. Having one piece of pumpkin pie with the family this season will indeed elevate your insulin, but only for an evening. Enjoy a moderately-portioned piece of that pie, and eat well for the rest of the week. As for management of heated political discourse around the dinner table, well, that’s far beyond the scope of this post.

Reference Article

The Carbohydrate-Insulin Model of Obesity: Beyond "Calories In, Calories Out"

PMID: 29971406