Calories-in/calories-out is a useful identity. But in isolation it tends to give people the wrong idea about successful weight loss. In particular, it says nothing about when a particular combination of calories in and calories out will lead to suffering and when it won't. As I emphasize in "Prevention is Easier Than Cure of Obesity":
By "what works" I mean not only being successful at losing weight and keeping it off, but also doing so with a minimum of suffering. As an economist, I would consider suffering a bad thing, even if suffering had no adverse effects on health whatsoever. But suffering also makes a weight loss program difficult to sustain, so suffering does have a bad effect on health. So minimizing suffering is crucial.
The calories-in/calories out identity is typically thought of this way:
Weight Gain in Calories = Calories Consumed - Calories Expended
What sneaks in with this arrangement of the identity is the questionable idea that calories consumed and calories expended are fixed quantities not subject to any deeper forces. Rearranging the identity gives a different perspective:
Calories Expended = Calories Consumed + Weight Loss in Calories
This rearrangement subtly hints at the idea that, holding calories consumed fixed, effective weight-loss that puts a lot of fatty acids and ketones into the blood stream from metabolized body fat might make one feel more energetic and so raise calories expended. Conversely, relatively ineffective weight loss combined with a low level of calories consumed will lead to internal starvation with all kinds of body signals going out to discourage energy expenditure and encourage the consumption of more calories. Those body signals are exactly the kinds of signals that can cause suffering.
Nina Teicholz attacks naive misunderstandings of calories in/calories out in her May 20, 2018 Los Angeles Times article "Counting calories won't reduce obesity. So why are we requiring restaurants to post them." I agree that posting calories is not a particularly effective public health intervention. I would go so far as to say it would be much more useful to post the insulin index of different types of food. (See "Forget Calorie Counting; It's the Insulin Index, Stupid." One benefit of requiring the posting of the insulin index for restaurant food is that the research would get done to measure the insulin index for more types of food.) The virtue of low-insulin-index food is that it has a high ratio of satiation to calories—where here by "satiation" I mean "being satiating." With food that has a high ratio of satiation to calories, it will feel natural to stop eating before consuming too many calories. You won't have to try so hard to stop.
Here is what Nina says about counting calories:
Although we've long held on to the intuitive idea that slimming down is merely a matter of beating the math — create a caloric deficit of 3,600 calories and lose a pound of fat — the evidence has been stacking up against it for more than a century.
Since the early 1900s, medical research has shown that people do lose weight on calorie-restricted diets — in the short term. But in most cases, they quickly gain it back. Reviewing hundreds of papers on dieting published already by 1959, two researchers concluded in the AMA Archives of Internal Medicine: "Most obese persons will not stay in treatment for obesity. Of those who stay in treatment, most will not lose weight, and of those who do lose weight, most will regain it."
Moreover, the researchers found, people usually put back on more weight than they'd lost. This cruel twist is due to the fact that a person's metabolic rate slows down to accommodate semi-starvation, but it doesn't bounce back, resulting in a stubbornly depressed metabolism. To maintain that weight loss, it appears a person must restrict calories for life — a state of deprivation that, as it turns out, few humans can sustain. The two AMA authors wrote that the most common "ill effects" of constant hunger include nervousness, weakness and irritability, and, to a lesser extent, fatigue and nausea.
Yet we seem committed to the myth that weight loss is merely a matter of calories in vs. calories out. That's why it's front-page news when researchers discovered that most participants in "The Biggest Loser" reality TV show didn't maintain their new, low weight — and that six years out, several weighed more than when they appeared on the show.
If counting calories in the usual way doesn't work, what does work? Nina points to some hints:
Insufficient sleep, for instance, may impair fat loss, as one small controlled trial concluded. Not getting enough sleep also increases the hunger hormone, ghrelin, according to another study. Chronic stress also appears to stimulate ghrelin, as well as the stress hormone cortisol, which is thought to weaken the body's ability to metabolize carbohydrates.
The most promising area of obesity research focuses on the effects of eating carbohydrates. Some 70 clinical trials now show that restricting carbohydrates is a highly effective way of fighting obesity. Low-carbohydrate diets are either equally or more effective than low-calorie diets, according to an analysis in JAMA.
One of the reasons low-carb diets work is precisely that they don't require counting calories. People are allowed to eat as much as they like, so long as they keep carbohydrates low. In part because foods with protein are satiating, people on this diet don't get hungry. Their metabolism doesn't slow down, and they aren't required to sustain a state of semi-starvation.
One recent survey of some 1,500 people found that more than a third of them were able to keep off more than 20 pounds and maintain a low-carb diet for two years or more. Another study, conducted at Stanford, found that subjects successfully lost weight without monitoring calories simply by eating high-quality "real" foods and more vegetables while reducing refined carbohydrates.
The big thing that Nina is missing is the idea of fasting, or time-restricted eating. As I say in "4 Propositions on Weight Loss," in my book the bottom line is this:
... for a large fraction of people, fasting—combined with avoiding sugar, bread, rice and potatoes—is a powerful, not-too-painful, tool for weight loss.
Don't miss these other posts on diet and health and on fighting obesity:
- Stop Counting Calories; It's the Clock that Counts
- 4 Propositions on Weight Loss
- Forget Calorie Counting; It's the Insulin Index, Stupid
- Obesity Is Always and Everywhere an Insulin Phenomenon
- The Problem with Processed Food
- Anthony Komaroff: The Microbiome and Risk for Obesity and Diabetes
- Letting Go of Sugar
- Prevention is Much Easier Than Cure of Obesity
- Which Is Worse for You: Sugar or Fat?
- Our Delusions about 'Healthy' Snacks—Nuts to That!
- My Giant Salad
- Using the Glycemic Index as a Supplement to the Insulin Index
- How Fasting Can Starve Cancer Cells, While Leaving Normal Cells Unharmed
- Why You Should Worry about Cancer Promotion by Diet as Much as You Worry about Cancer Initiation by Carcinogens
- Good News! Cancer Cells are Metabolically Handicapped
- How Sugar, Too Much Protein, Inflammation and Injury Could Drive Epigenetic Cellular Evolution Toward Cancer
- Meat Is Amazingly Nutritious—But Is It Amazingly Nutritious for Cancer Cells, Too?
- The Keto Food Pyramid
- Sugar as a Slow Poison
- How Sugar Makes People Hangry
- Why a Low-Insulin-Index Diet Isn't Exactly a 'Lowcarb' Diet
- Hints for Healthy Eating from the Nurse's Health Study
- The Case Against Sugar: Stephan Guyenet vs. Gary Taubes
- The Case Against the Case Against Sugar: Seth Yoder vs. Gary Taubes
- Gary Taubes Makes His Case to Nick Gillespie: How Big Sugar and a Misguided Government Wrecked the American Diet
- Against Sugar: The Messenger and the Message
- A Conversation with David Brazel on Obesity Research
- Magic Bullets vs. Multifaceted Interventions for Economic Stimulus, Economic Development and Weight Loss
- Mass In/Mass Out: A Satire of Calories In/Calories Out
- Carola Binder: The Obesity Code and Economists as General Practitioners
- Carola Binder—Why You Should Get More Vitamin D: The Recommended Daily Allowance for Vitamin D Was Underestimated Due to Statistical Illiteracy
- Jason Fung: Dietary Fat is Innocent of the Charges Leveled Against It
- Faye Flam: The Taboo on Dietary Fat is Grounded More in Puritanism than Science
- Diseases of Civilization
- Katherine Ellen Foley—Candy Bar Lows: Scientists Just Found Another Worrying Link Between Sugar and Depression
- Ken Rogoff Against Sugar and Processed Food
- Kearns, Schmidt and Glantz—Sugar Industry and Coronary Heart Disease Research: A Historical Analysis of Internal Industry Documents
- Eating on the Road
- Intense Dark Chocolate: A Review
- In Praise of Avocados
- Salt Is Not the Nutritional Evil It Is Made Out to Be
- Confirmation Bias in the Interpretation of New Evidence on Salt
- Whole Milk Is Healthy; Skim Milk Less So
- Is Milk OK?
- How the Calories In/Calories Out Theory Obscures the Endogeneity of Calories In and Out to Subjective Hunger and Energy
- Putting the Perspective from Jason Fung's "The Obesity Code" into Practice
- 'Forget Calorie Counting. It's the Insulin Index, Stupid' in a Few Tweets
- Julia Belluz and Javier Zarracina: Why You'll Be Disappointed If You Are Exercising to Lose Weight, Explained with 60+ Studies (my retitling of the article this links to)
- Diana Kimball: Listening Creates Possibilities
- On Fighting Obesity
- The Heavy Non-Health Consequences of Heaviness
- Analogies Between Economic Models and the Biology of Obesity
- Debating 'Forget Calorie Counting; It's the Insulin Index, Stupid'
- Podcast: Miles Kimball Explains to Tracy Alloway and Joe Weisenthal Why Losing Weight Is Like Defeating Inflation
Also see the last section of "Five Books That Have Changed My Life" and the podcast "Miles Kimball Explains to Tracy Alloway and Joe Weisenthal Why Losing Weight Is Like Defeating Inflation." If you want to know how I got interested in diet and health and fighting obesity and a little more about my own experience with weight gain and weight loss, see my post "A Barycentric Autobiography."