“Calories in vs Calories out” goes beyond food and exercise.
There’s an important distinction to be made between CICO and “eat less, move more.” But people, especially some CICO advocates, tend to conflate the two.
“Eat less, move more” only takes into account the calories you eat and the calories you burn through exercise and other daily movement. But CICO is really an informal way of expressing the Energy Balance Equation, which is far more involved.
The Energy Balance Equation—and therefore CICO—includes all the complex inner workings of the body, as well as the external factors that ultimately impact “calories in” and “calories out.”
Imperative to this, and often overlooked, is your brain. It’s constantly monitoring and controlling CICO. Think of it as mission control, sending and receiving messages that involve your gut, hormones, organs, muscles, bones, fat cells, external stimuli (and more), to help balance “energy in” and “energy out.”
It’s one hell of a complicated—and beautiful—system.
Dilemma 1: “My hormones are wreaking havoc on my metabolism, and I can’t stop gaining weight. Help!”
Hormones seem like a logical scapegoat for weight changes.
And while they’re probably not to blame as often as people think, hormones are intricately entwined with energy balance.
But even so, they don’t operate independently of energy balance.
In other words, people don’t gain weight because “hormones.”
They gain weight because their hormones are impacting their energy balance.
This often happens during menopause or when thyroid hormone levels decline.
Take, for example, triiodothyronine (T3) and thyroxine (T4), two thyroid hormones that are incredibly important for metabolic function. If levels of these hormones diminish, weight gain may occur. But this doesn’t negate CICO: Your hormones are simply influencing “energy out.”
This may seem a bit like splitting hairs, but it’s an important connection to make, whether we’re talking about menopause or thyroid problems or insulin resistance or other hormonal issues.
By understanding CICO is the true determinant of weight loss, you’ll have many more tools for achieving the outcome you want.
Suppose you’re working from the false premise hormones are the only thing that matters. This can lead to increasingly unhelpful decisions, like spending a large sum of money on unnecessary supplements, or adhering to an overly restrictive diet that backfires in the long run.
Instead, you know results are dependent on the fact that “energy in” or “energy out” has changed. Now, this change can be due to hormones, and if so, you’ll have to make adjustments to your eating, exercise, and/or lifestyle habits to account for it. (This could include taking medication prescribed by your doctor, if appropriate.)
Research suggests people with mild (10-15% of the population) to moderate hypothyroidism (2-3%) may experience a metabolic slow down of 140 to 360 calories a day.
That can be enough to lead to weight gain, or make it harder to lose weight. (One caveat: Mild hypothyroidism can be so mild many people don’t experience a significant shift in metabolic activity, making it a non-issue.)
What’s more, women suffering from polycystic ovary syndrome, or PCOS (about 5-10%), and those going through menopause, may also experience hormonal changes that disrupt energy balance.
So, it’s important to understand your health status, as that will provide valuable information about the unique challenges involved and how you should proceed.
Dilemma #3: “I’m only eating 1,000 calories a day and I’m still not losing weight!”
So what gives?
The conclusion most people jump to: Their metabolism is broken. They’re broken. And CICO is broken.
But here’s the deal: Metabolic damage isn’t really a thing. Even though it may seem that way.
Now, their energy balance challenge could be related to a hormonal issue, as discussed above. However, when someone’s eating 1,000 calories a day but not losing weight, it’s usually due to one of the two reasons that follow.
(No matter how simple they sound, this is what we’ve seen over and over again in our coaching programme, with over 100,000 clients.)
Reason #1: People often underestimate their calorie intake.
It’s easy to miscalculate how much you’re eating, as it’s usually unintentional. The most typical ways people do it:
- They underestimate portions. (For example, without precisely measuring “one tablespoon of peanut butter,” it might actually be two, which adds 90 calories each time you do it)
- They don’t track bites, licks, and tastes of calorie-dense foods. (For example, your kid’s leftover mac and cheese could easily add 100 calories)
- They don’t record everything in the moment and forget to log it later on
- They “forget” to count foods they’d wished they hadn’t eaten
Don’t believe this can be a big issue?
A landmark study, and repeated follow up studies, found people often underestimate how much they eat over the course of a day, sometimes by more than 1,000 calories.
I’m not bringing this research up to suggest it’s impossible to be realistic about portion sizes. But if you aren’t seeing results on a low-calorie diet, it’s worth considering that underestimation may be the problem.
Reason #2: People overeat on the weekends.
Work weeks can be stressful and when Friday night rolls around, people put their guard down and let loose.
(You probably can’t relate, but just try, okay?)
Here’s how it goes: Let’s say a person is eating 1,500 calories a day on weekdays, which would give them an approximate 500-calorie deficit.
But on the weekends, they deviate from their plan just a little.
- Drinks with friends and a few slices of late night pizza on Friday
- An extra big lunch after their workout on Saturday
- Brunch on Sunday (“Hey, it’s breakfast and lunch, so I can eat double!)
The final tally: An extra 4,000 calories consumed between Friday night and Sunday afternoon. They’ve effectively canceled out their deficit, bumping their average daily calories to 2,071.
The upshot: If you have slashed your calories dramatically, but you aren’t seeing the expected results, look for the small slips. It’s like being a metabolic detective who’s following—perhaps literally—the bread crumbs.
Dilemma #2: “I’m eating as much as I want and still losing weight, so this diet is better than all the others!”
This might be the top reason some people reject CICO.
Say someone switches from a diet of mostly processed foods to one made up of mostly whole, plant-based foods. They might find they can eat as much food as they want, yet the pounds still melt away.
People often believe this is due to the “power of plants.”
Yes, plants are great, but this doesn’t disprove energy balance.
Because plant foods have a very-low energy density, you can eat a lot of them and still be in a calorie deficit. Especially if your previous intake was filled with lots of processed, hyperpalatable “indulgent foods.”
It feels like you’re eating much more food than ever before—and, in fact, you really might be.
On top of that, you might also feel more satiated because of the volume, fiber, and water content of the plants.
All of which is great. Truly. But it doesn’t negate CICO.
Or take the ketogenic diet, for example.
Here, someone might have a similar experience of “eating as much as they want” and still losing weight, but instead of plant foods, they’re eating meat, cheese, and eggs. Those aren’t low-calorie foods, and they don’t have much fiber, either.
As a result, plenty of low-carb advocates claim keto offers a “metabolic advantage” over other diets.
Here’s what’s most likely happening:
- Greater intake of protein increases satiety and reduces appetite
- Limited food choices have cut out hundreds of highly-processed calories they might have eaten otherwise (Pasta! Chips! Cookies!)
- Reduced food options can also lead to “sensory-specific satiety.” Meaning, when you eat the same foods all the time, they may become less appealing, so you’re not driven to eat as much
- Liquid calories—soda, juice, even milk—are generally off-limits, so a greater proportion of calories are consumed from solid foods, which are more filling
- Higher blood levels of ketones—which rise when carbs are restricted—seem to suppress appetite
For these reasons, people tend to eat fewer calories and feel less hungry.
Although it might seem magical, the keto diet results in weight loss by regulating “energy in” through a variety of ways.
You might ask: If plant-based and keto diets work so well, why should anyone care if it’s because of CICO, or for some other reason?
Because depending on the person—food preferences, lifestyle, activity level, and so on—many diets, including plant-based and keto, aren’t sustainable long-term. This is particularly true of the more restrictive approaches.
And if you (or your client) believe there’s only one “best diet,” you may become frustrated if you aren’t able to stick to it. You may view yourself as a failure and decide you lack the discipline to lose weight. You may even think you should stop trying.
None of which are true.
Your results aren’t diet dependent. They’re behaviour dependent.
Maintaining a healthy body (including a healthy body weight) is about developing consistent, sustainable daily habits that help you positively impact “energy in” and “energy out.”
This might be accomplished while enjoying the foods you love, by:
- Eating until you’re 80% full
- Eating slowly and mindfully
- Eating more minimally processed foods
- Getting more high-quality sleep
- Taking steps to reduce stress and build resilience
It’s about viewing CICO from 30,000 feet and figuring out what approach feels sane—and achievable—for you.
Sure, that might include a plant-based or a keto diet, but it absolutely might not, too. And you know what?
You can get great results either way.
How to cheat the system
Maximise protein and fibre.
Consuming higher amounts of protein increases satiety, helping you feel more satisfied between meals. And consuming higher amounts of fibre increases satiation, helping you feel more satisfied during meals.
These are both proven in research and practice to help you feel more satisfied overall while eating fewer calories, leading to easier fat loss.
This advice can sound trite, I know. In fact, someday when there are nutrition coach robots, “eat more protein and fibre” will probably be the first thing they’re programmemed to say.
But the truth is, most people trying to lose weight still aren’t focused on getting plenty of these two nutrients.
And you know what? It’s not their fault.
When it comes to diets, almost everyone has been told to subtract. Take away the “bad” stuff, and only eat the “good” stuff.
But there’s another approach: Just start by adding.
If you make a concerted effort to increase protein (especially lean protein) and fiber intake (especially from vegetables), you’ll feel more satisfied.
You’ll also be less tempted by all the foods you think you should be avoiding. This helps to automatically “crowd out” ultra-processed foods.
Which leads to another big benefit: By eating more whole foods and fewer of the processed kind, you’re actually retraining your brain to desire those indulgent, ultra-processed foods less.
That’s when a cool thing happens: You start eating fewer calories without actively trying to—rather than purposely restricting because you have to.
That makes weight loss easier.
Starting is simple: For protein, add one palm of relatively lean protein—chicken, fish, tempeh—to one meal. This is beyond what you would have had otherwise. Or have a Super Shake as a meal or snack.
For fibre, add one serving of high-fiber food—in particular vegetables, fruit, lentils and beans—to your regular intake. This might mean having an apple for a snack, including a fistful of roasted carrots at dinner, or tossing in a handful of spinach in your Super Shake.
Try this for two weeks, and then add another palm of lean protein, and one more serving of high-fibre foods.
Besides all the upside we’ve discussed so far, there’s also this:
Coming to the table with a mindset of abundance—rather than scarcity—can help you avoid those anxious, frustrated feelings that often come with being deprived of the foods you love.
So instead of saying, “Ugh, I really don’t think I can give up my nightly wine and chocolate habit,” you might say, “Hey, look at all this delicious, healthy food I can feed my body!”
(And by the way, you don’t actually have to give up your wine and chocolate habit.. at least not to initiate progress, or ever even.)