The topic of Calories in Versus Calories Out (CICO for short) is one of the most argued about concepts in nutrition with strong supporters who say that CICO is the basis of weight management and body composition while others say CICO does not work and that managing weight and bodyfat is a hormonal/metabolic issue. So, what’s the deal?
CICO is a fundamental concept underpinning all attempts to regular body composition (fat mass vs lean mass) and body weight and a fact proven many times over so why are many people (even highly respected research scientists) debating its merit?
The issue comes down to the fact that although CICO is real – MANY factors, including hormone levels – dramatically influence calories in and out because human beings are complex organisms!
CICO is about more than just food intake and exercise!
CICO is about the energy balance equation which takes into all the internal and external factors that affect how many calories you burn and how many calories you consume and absorb. Let’s take a look at some of these factors:
Factors that influence Caloric Intake (what we eat and drink and absorb) include:
Appetite – is influenced by hormones that influence hunger and satiety
Food Consumption – is influenced by culture, food that is available, sleep quality, energy density of foods consumed, taste, education, and socioeconomic status
Calorie Absorption – is influenced by Macronutrient Mix (percentage of fat, carb and protein eaten); how food is prepared; your age (digestion and nutrient absorption decrease with age); microbiome make-up (specific mix of bacteria in your gut); health status; and medications
Psychological State – is influenced by stress levels; mindset; level of self-esteem; and quality and length of daily sleep
Factors that influence Calorie Expenditure (Calorie Burn) include:
Basal Metabolic Rate – is influenced by height, weight, age, sex, hormone levels, genetics, health status, medications, certain herbal supplements, quality of sleep and even food intake and timing!
Calories burned during exercise – is influenced by exercise ability and fitness level; height; weight; age; sex; intensity of exercise; duration of exercise; frequency of exercise; hormonal status and sleep quality.
Calories burned during non-exercise activity – is influenced by health status; stress levels; hormonal status; occupation; leisure activity; and culture.
Calories burned from process food and beverage intake – often called the "Thermic Effect of Food" – is influenced by types of food you eat; level of food processing; and macronutrient percentages of food consumed.
Although CICO is simple managing it to get the results you want is not so simple!
There’s no getting around it: If you (or a client) aren’t losing or gaining weight the way you want to - you either need to adjust calories in or increase calories burned or both! BUT – there is more than one way to skin this cat.
For instance, you may need to:
· Get more high-quality sleep to better regulate hunger hormones, improve recovery, and increase metabolic output
· Try stress reduction strategies including meditation,deep breathing, and spendingtime in nature
· Increase your daily non-exercisemovement by parking the car a few blocks away from your destination, taking the stairs, and/or standing while you work
· Trade some high-intensity exercise for lower-intensity activities, in order to aid recovery and reduce systemic stress or conversely most exercisers need to add High Intensity Interval Training to their exercise program.
· Improve the qualityof what you’re eating, as opposed to reducing the quantity. This can allow you to eat more food with fewer total calories · Experiment with the macronutrient makeup of what you eat. For example: eating more protein and fiber, or increasing carbs and lowering fats, or vice versa
· Experiment with thefrequency and timing of your meals and snacks, based on personal preferences and appetite cues
· Consider temporarily tracking your food intake—via hand portions or weighing/measuring—to ensure you’re eating what you think you’re eating (as closely as reasonably possible)
· Evaluate and correctnutritional deficiencies, for more energy during workouts (and in everyday life)
· Consult with your physician or specialists if consistent lifestyle changes aren’t moving the needle
Common CICO Issues
“I’ve eat the same way all the time, but suddenly I started gaining weight.”
More than likely, “energy in” or “energy out” did change, but in a way that felt out of control or unnoticeable.
The issues could be:
· Slight increases in food intake, due to changes in your mood, hunger, or stress levels
· An increase in the amount of energy absorbed—caused by new medication, an unknown medical condition, or a history of chronic dieting
· Physiological changes that resulted in fewer calories burned during exercise and at rest
· Chronic pain, provoking a dramaticdecrease in non-exercise calorie burn due to reduced movement
· Significant changes to sleep quality and/or quantity, impacting metabolic output and/or food consumed
In all of these cases, CICO is still valid. Energy balance just shifted in subtle ways, due to lifestyle and health status changes, making it hard to perceive the changes.
“My hormones have changed, and I can’t stop gaining weight.”
Hormones are a common scapegoat for weight loss challenges, and while they’re probably not to blame as often as people think, hormonesare 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 of “hormones.”
They gain weight because their hormones are impacting their energy balance equation. One of many examples is low thyroid hormone levels which often happens during menopause.
Changing hormone levels can and DO impact calorie burn and thereby change the energy balance equation by changing calorie burn!
This discussion 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. Even people who have hormonal issues resulting in significantly lower levels of calorie burn can successfully lose weight by understanding and using many approaches that can increase their overall calorie burn and decrease their calorie intake!
“I’m only eating 1,000 calories a day and I’m still not losing weight!”
This is a common statement heard frequently from many people so what is the story here?
People love to blame weight loss failure on a slow or broken metabolism. But is that really what is going on in most cases?
When someone says they are eating 1,000 calories a day but not losing weight, it’s usually due to one of the two reasons.
People often underestimate their calorie intake.
· 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
A landmark 1992 research study along with several follow-up studies showed that people often underestimate how much they eat over the course of a day, sometimes by more than 1,000 calories.
People overeat on the weekends.
Many people eat much more over the weekends which can completely sidetrack any success in weight management!
For example: 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 from 1,500!
“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 feelslike 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.
People on the Ketogenic Diet often perceive that they can “eat 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 that 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 caloriesand feel less hungry. Although it might seem magical, the keto diet results in weight loss by regulating CICO – just like ANY successful weight loss approach.
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 depend on your consistent behaviors and habits!
It is all about developing consistent, sustainable daily habits that help you positively impact CICO.
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 figuring out what approach feels sane—and achievable—for you.
“I can’t gain weight no matter how much I eat.”
Some people struggle to gain weight - especially younger athletes and people who are very, very active at work. (people with jobs like construction workers.). It can also be challenging to regain lost weight after an illness.
When someone intentionally eats more food but does not gain weight it may seem like CICO is not working. However, the story usually goes something like this: A person eats six big meals on a particular day, but the following day, they only ate two small meals because they were e really busy so they didn’t even think much about it.
They remember the heavy eating day but forget the low food intake day because they are not tracking food intake by writing down what they eat every time they eat.
The solution is to aim for a consistent daily calorie intake you can stick with and track your food intake daily for several weeks to make sure you are eating enough to cause weight gain.
Some People increase their activity level when they increase calorie intake
When some people take in more calories – they have more energy available so they move more such as starting to take the stairs instead of an elevator, pacing while on the phone, increasing the intensity of their workouts, or fidgeting in their seats.
In this case the increase in calorie burn can eliminate the calorie surplus from increased calories in resulting in no weight gain!
