This post was written by Dr. Yoni Freedhoff, a family doctor and Assistant Professor at the University of Ottawa. The views expressed herein are his. For more from Yoni, visit his website and follow him on Twitter.
First, a confession.
I count calories. Haven’t missed an entry since May 7th, 2011.
No, I don’t have an eating disorder. Yes, some days my calories counts are stupidly high (Could someone please invent some low calorie chicken wings and ribs?).
With that off my chest, let’s get into some unfortunate truths about people, weight, and calories.
You Aren’t a Walking Math Formula
Public health authorities often tell us that 3,500 calories one way or the other will lead to a pound of gain or loss, but unfortunately many of our bodies missed that memo. Both over- and under- feeding experiments have demonstrated that people gain weight at different rates despite equivalent degrees of caloric excess or restriction. In one now-famous experiment, researchers overfed sixteen young men and women by 1,000 calories a day for eight weeks in tightly controlled conditions. The expectation, of course, was that everyone ought to gain 16 pounds, as would be predicted by a 56,000-calorie eight-week excess divided by 3,500 calories per pound. Yet only one person gained that much. The average weight gain was just over 10 pounds, and one individual (likely the guy we all know and hate who can eat whatever he wants and not gain weight) only gained three.
You can think of it a bit like fuel economy in cars. Some of us are walking around driving Humvees while others drive hybrids. The Humvee drivers are the folks who get virtually no fuel economy for their energy stores and consumption. Humvee drivers are like that study subject who barely gained weight despite eight weeks of over feeding, eating whatever they want without having to worry about their waists. The hybrid drivers are the folks who can look at an indulgence and gain weight, and while their incredibly efficient metabolisms may well see them surviving the zombie apocalypse, in our current Willy Wonkian wonderland of calories, they gain weight almost effortlessly.
The Quality of Calories MatterS
Consider some incredibly cool data from an experiment published in the journal Food and Nutrition Research a few years back . Researchers compared the “thermic effect of food” (TEF, or the energy your body uses to actually process and absorb what you're eating) following the consumption of a whole food grilled cheese sandwich (multigrain bread with whole grain and intact sunflower seeds along with cheddar cheese) versus a processed food grilled cheese sandwich (white bread and Kraft singles).
Generally a person's TEF is thought to account for 10 percent of their day’s total calorie burn. What this experiment found was that the whole food grilled cheese, while equal in calories as well as in protein, carb, and fat ratios, required nearly 50 percent more energy to absorb than its highly processed counterpart. This means the calories available to your body for storage can be much higher when they come from processed foods versus whole.
The Types of Calories Matter
I’m not here to debate carbs, proteins, or fats, but in my opinion, they matter. They matter in terms of that thermic effect of food I was talking about before, but they also matter in terms of satiety or fullness. If you eat 500 calories of refined carbohydrates, they’ll likely leave you far less full than 500 calories of fat and protein. And while tightly controlled experiments demonstrate that regardless of whether or not calories come from carbs, fats, or protein, in those strict laboratory settings, weight is gained or lost simply according to total calories. But we (hopefully) don't live in a metabolic ward. Instead, we free-range humans enjoy the luxury of eating in response to and in accordance with our many needs and desires and use food not simply for fuel, but also for comfort and celebration.
That said, at the top of the heap of eating needs and desires is hunger. If you’re less full because of the types of foods you’re eating, you’re likely to eat more. It’s also worth noting that the qualities of proteins, carbohydrates, and fats you consume will vary, and that as far as the impact of diet on chronic disease, whole grains trump refined, fish trumps cow, and unsaturated fats trump all others .
To sum it up: People have different fuel efficiencies, whereby two people eating the same number of calories may see markedly different impacts of those calories upon their weights; the more processed a food the more calories it’ll effectively make available to your body; and some foods will leave you hungrier and in turn (given our caloric modern day wonderland) lead you to eat more.
Why, then, would I ever count calories?
Why I Still Choose to Count Calories
I count because none of the aforementioned caloric shortcomings gets past these three truths.
1. People do obey the laws of physics (albeit in accordance with their own internal energy efficiencies).
Regardless of your personal internal equations, if you consistently eat more calories than you burn, you’ll tend to gain weight. Some people may gain incredibly quickly, some incredibly slowly, but we live in a universe governed by unbreakable physical laws, and that one about conservation of energy is going to matter (energy is neither created nor destroyed, it just changes form). Putting this more plainly, if you happen to have one of those bodies that’s demonstrated itself to be truly efficient at gaining weight, and you happen to regularly consume more energy than your body burns, your body will dutifully store some of that energy for the future. It’s also true that the types of foods you eat will undoubtedly affect the total calories you consume, but that still doesn’t change the fact that energy balance does affect your weight.
2. There’s no more readily available source of energy information than calories.
It would be wonderful if there were more accurate numbers to track — if for instance there were what might be described as “bioavailable” calories listed on packages and menus. (“Bioavailable” would reflect the impact that processing and macronutrient ratios might have on the calories a food might possess that are actually available to your body.). Unfortunately, no such measure exists. So for now, we’re stuck with calories.
3. Food diaries are far and away the most efficient means to maximize weight loss.
Food diarizing has been shown to lead practitioners to lose twice as much weight as those not tracking, and when you’re good at it (which may take a month or two), it’ll take you less than three minutes a day to do one. And while some might feel those results are just a coincidence when paired with caloric knowledge, I don’t.
Sure, it’s nice to have a rough idea of what your energy intake looks like, but more valuable than numbers is the actual act of tracking food intake. It’s a behavior that truly takes seconds to minutes a day to do, but each and every time you pull out your app or diary, you remind yourself of your healthy living desires and strategies. It’s through regular and conscious efforts and reminders that new habits are formed, and any behavior that helps you to keep your goals and intentions at the forefront of your busy mind is a good one.
What I don’t like about food diarizing is when it becomes punitive or judgmental. Food diaries aren’t there to tell you what you are or aren’t allowed. A food diary is simply a source of information to help inform your decisions, as well as an incredibly powerful habit-building tool. Sure, you can diarize anything and get the habit-building benefits, but think of calories as the currency of weight: If weight’s your concern, tracking its currency is likely to be a good bet. That said, don’t forget that with calories as currency, the exchange rate varies constantly. Not knowing the exchange rate doesn’t mean that price tags don’t matter, just that some will do more and less damage than you might have imagined at point of purchase.
Should I Keep a Food Diary?
Why fix what isn’t broken? If you’ve found a pattern of eating that leaves you happily satisfied with your weight, your health, and your lifestyle, it’s doubtful a food diary or calorie counts will bring much to your table.
On the other hand, if you aren’t satisfied with your weight, health, or lifestyle, I’d encourage you to consider a one-month trial of tracking. Food diary apps are plentiful, and once you’ve entered in your usual foods, record keeping takes all of one or two minutes at most a day.
Diarizing isn’t meant to replace your dietary strategy; it’s there to supplement it. Whether you’re intermittently fasting, following a Paleo or low-carb plan, or even just doing your own thing, calorie tracking and food diarizing, regardless of their imperfections, oversights, and shortcomings, may be just the thing you need to figure out why you might be stuck.
Photo courtesy of Dr. Yoni Freedhoff.
Do you count calories? Why or why not? Sound off in the comments below!