The macros based, calories in/calories out model is the most accurate one we have, even if it’s not perfect. Basically all current research revolves around this model, since base calorie metabolism is just what bodies work on.
At the same time, it’s not just about the exact mechanics of metabolism, and there's a lot that's unknown.
Non CICO diets still work based on the CICO principles - so, any diet can be used to achieve the same results so long as these principles are followed.
Water weight, intestinal issues, poor tracking, problems with weighing yourself properly, not knowing your metabolism, or getting too obsessed with a certain diet method can all obscure your results, making it seem like CICO isn’t really working.
No particular method is perfect, but CICO gives us a framework with which to understand why some diets work and others don’t.
A friend of mine recently shared that she hadn’t initially trusted in the concept of calories in, calories out - but, thanks to me, she tried it to amazing results.
This is a topic I’ve covered elsewhere before. If you want an overview of why calories matter (and why people often estimate their metabolism wrong) check out this post on understanding your metabolism. For an overview of how to use macros to achieve various fitness goals, check out these posts.
I would like to point out that virtually the entire current body of quality diet research is based on macros, and by extension calories. This is because our bodies are simply designed to break down our foods into their base components (macronutrients and micronutrients) and then process them through very specific energy pathways. Calories matter because they're literally how your body derives energy in order to continue functioning.
Research repeatedly shows that we gain weight when we eat additional calories than our body needs each day, and lose weight when we eat fewer than our body needs each day. This is referred to as the “calories in, calories out” (CICO) model. The CICO model is the most well-researched and evidence-based model we have.
At the same time, CICO often comes under fire from skeptics who claim that weight gain or loss is due to other issues, like our carb or fat consumption, whether or not we consume a lot of refined carbohydrates (sugars), and more.
These theories have generally been based on little to no evidence, or are based on a misunderstanding of the current evidence as it stands. In some cases, it is true that there are other factors at play than just calories in and out, but these factors usually only throw off the overall equation by very small amounts.
The best and most practical criticism of CICO is that it’s terribly hard to do accurately. All the numbers that make up our metabolism are variable, and can change from day to day or week to week. Even the calories that we consume aren’t a set amount - if you have an issue with your intestines, for example, your body won’t absorb all the calories in your food, meaning that some of them are being lost.
So, CICO isn’t as simple as a math equation of (calories you eat) minus (calories you burn). The math is there, and it is real, but it’s not as simple as all that.
Another valid criticism of CICO is that while it does a good job of explaining how our bodies work, it doesn’t do a great job of explaining how we can actually lose or gain weight. The stereotypical CICO recommendation is simply “eat less and move more”, but this recommendation is as simple and unhelpful as telling a depressed person to “smile more”.
These simple and unhelpful recommendations can often do more harm than good - how can you move more within the context of your life, while also not creating overuse issues? How can you eat less within the context of your life, without eating so little that it causes irritability, hunger, and health issues? What is the best dietary approach to do so? How can you take steps to reduce depression so that you’re generally happier?
I remember a classic joke from my basketball coach, when you’d ask him what you could do to win: “Well, you have to get better at putting the ball into the basket than the other team."
So, saying that CICO works is sometimes so clear as to be self-evident, but that’s exactly the problem.
It is important to realize that literally any diet that works is working because of the principles of CICO working. A diet may or may not be actually based on CICO, but it works based on the same underlying principles - by somehow getting you to eat fewer calories over time.
It might do this by making you eat vegetarian, or paleo, or low carb, or high fat, or whatever other approach you take - but that's still CICO in the end.
The typical approach “clean eating” - defining certain foods as “good” and certain foods as “bad”, and encouraging you to eat the good foods and avoid the bad ones. Unfortunately, no two clean eaters can ever seem to agree on what a good food or bad food is, and they’re constantly fighting about it!
The reason clean eating diets tend to work is that they encourage you to focus on eating a lot of the foods which are highly filling relative to their calorie content (fruits, veggies, proteins, minimally processed foods) while avoiding the ones which are high calorie, minimally filling, and also likely to be hella delicious (processed foods, sweets, some carb sources, “hyperpalatable” foods like fast food, etc.).
By cutting out entire food groups (particularly ones which have an unnecessarily large contribution to your overall calories), clean eating diets work by convincing you to eat less food overall. Of course, this is also why they often don’t work - because they don’t focus on overall calories. Even though you’re eating less of a certain food group, you might just eat more of another food group to make up for it if you're not paying attention.
Some clean eating diets solve this problem by doubling down further - strictly limiting you to only a handful of foods or repeated meals - but of course, this is so restricting as to be very difficult to follow, not to mention more likely to cause malnourishment due to the limited number of foods you can eat.
This is not really much different than the approach of a CICO diet, which attempts to work a similar effect on your diet, but it's done with a hammer instead of a scalpel - there's less precision involved.
Clean eating diets also come with a lot of potential drawbacks: unnecessary demonization/moralization of food groups, complete avoidance of comfort foods, and so on. I’ve written before about the logical endpoint of a lot of clean eaters - a confused and bizarre minefield of constantly shifting, anxiety-inducing “dos” and “don’ts”, none of which are really based in serious science.
CICO doesn’t always SEEM to work. This is because there are a lot of phenomenon that can make it seem off, including:
Water weight. Water weight can shift a few pounds from day to day, and women tend to hold more water at certain parts of their monthly cycle. If you’re on track to lose 1lb/week, this means any actual weight loss may not show up for several weeks due to these fluctuations. However, over time, a graph of your weight would still trend downwards, even if there’s short term up and down spikes. I recommend using a rolling average tool for this reason.
Intestinal issues. As mentioned above, intestinal issues can cause incomplete absorption of food in the gut, meaning that you can excrete some of your calories. You may have thought of all the calories that enter your mouth as “calories in”, but that’s not fully accurate.
Poor tracking of diet. People are absolutely terrible at tracking themselves mentally unless held accountable using some kind of tracking method. If you’re not tracking, chances are you don’t have actually have much of a clue how many calories you’re eating (or burning).
Inaccurate calorie burn estimates. Devices like the Fitbit, Apple Watch, and more purport to give you an accurate estimate of how many calories you're burning - but they're not actually very accurate. Likewise, calorie burn counts on heart rate monitors and on cardio equipment can be useful in strict cardio scenarios, but aren't actually anywhere near an accurate estimate of how many calories you're burning during other types of exercise - so, you'll often get hugely inflated numbers when using them to track anything else, which manufacturers conveniently fail to mention.
Not accounting for NEAT. Non exercise activity thermogenesis (NEAT) is a fancy term for "the calories you're burning through activity during the day when not working out", and is distinct from our base metabolism and our exercise caloric burn. People who move very little throughout the day will burn fewer calories than the ones who have something like an intense job where they move around a lot. Since NEAT is hard to account for, this is often where a lot of confusion can show up.
Weighing yourself. In order to track real changes in body mass, you should weigh yourself in the morning using the same scale you’ve used previously - changes in water weight, the amount of food in your stomach, or how accurate one scale is compared to another can all throw your numbers off and obscure what’s actually going on. If you're weighing yourself at different times of day, these factors can throw everything off.
Not understanding your metabolism. As explored in the metabolism article above, your metabolism is a lot more complex and variable than people think. Luckily, you can reverse engineer your metabolism after the fact, if you have perfect tracking and weigh yourself daily. It’s a hard solution, but it’s the only one that really worked.
Genetics. Genetics really do matter, and can result in some confusion. It's unclear exactly how genetics impact things like our base metabolism, NEAT, recovery rates from exercise and psychological reaction to exercise, and more, but the effect is massive. For this reason, genetics really can throw a wrench in the works, though it would be uncommon that genetics would really have a huge impact.
“X worked for me, so CICO isn’t real!” This is usually just because of some misunderstanding of what CICO is and how it works. CICO isn’t exclusive of others kinds of diets - many diets can be both CICO and something else. Chances are that if you think CICO doesn't work, it's because of some misunderstanding of one of the above principles or some other part of the process.
The Three Jewels
In Buddhism, there’s a concept called the three jewels (or three treasures in Taoism) - referring to the Buddha (the historical figure), Dharma (teachings of the Buddha), and Sangha (the Buddhists who help spread the teachings).
In college, I took a class on Buddhism, and the question of why they would name these “jewels” came up. After all, the primary goal of Buddhism is to cast off any kind of obsession with materialism - so, why use the concept of a jewel, which is itself a symbol of material wealth?
The answer is that sometimes we need to be misled in order to be put on the right path. While a true Buddhist would be unconcerned by material wealth, the outsider (who may still be obsessed with earthly treasures themselves) would be drawn in by the idea of a precious gem. That it’s not truly a gem at all, but instead a religious concept, is sort of a bait and switch that tricks you into being enticed to the right path.
Likewise, any particular dietary approach can work, so long as they follow the rules set forth in the CICO model. This instagram graphic by my friend Carter Good hits the nail on the head - it’s not about the specific strategy you use to achieve a calorie deficit, but about getting into that calorie deficit in the first place. Any particular diet can be wrong in the sense that it’s not done properly, but likewise, any particular diet can be done properly.
Macros work, even when they don’t seem to. The issue is not whether or not they work, but what methods we use to achieve the changes we want in our diet, and thus, the long term changes in our physique.
- Understanding Your Actual Metabolism
- Programming Your Macros Part 1: General Health and Wellness
- Programming Your Macros Part 2: Gaining Muscle
- Programming Your Macros Part 3: Weight Cutting and Weight Loss
- The Dangers of Clean Eating (And Other Food Babe Related Things)
- Clean Eating and IIFYM Are The Same Damn Thing
- No, I Won't Help You Lose Weight
Are you interested in perfecting your deadlift and building legendary strength and muscle? Check out my free ebook, Deadlift Every Day. Or maybe a well-rounded beginners program for those looking to build strength, muscle, and endurance? Check out my other free ebook, GAINS.