What does CICO mean? (calories in calories out)
I keep seeing CICO mentioned everywhere on this forum. What is it exactly? Is it a diet? A philosophy? Do I need to follow it?
CICO = Calories In, Calories Out. It's not a diet — it's the fundamental law of energy balance.
- Eat more calories than you burn = weight gain
- Eat fewer calories than you burn = weight loss
- Eat roughly what you burn = weight maintenance
EVERY diet works through this mechanism, whether it admits it or not. Keto works because people eat less. IF works because people eat less. Vegan works because people eat less.
CICO doesn't tell you WHAT to eat, just HOW MUCH. It's the framework, not the whole picture.
Good explanation. I'd add that while CICO is the FUNDAMENTAL mechanism, it's overly simplistic as a complete framework. The "calories out" side is complex — affected by metabolism, hormones, activity, and the thermic effect of food.
Saying "just eat less" is technically correct but ignores the psychological and physiological factors that make eating less difficult.
My issue with the CICO crowd: it reduces nutrition to a math problem and ignores food quality, satiety, hormonal effects, and psychological factors. 200 calories of chicken is not the same as 200 calories of candy from a HEALTH perspective.
@antiDietCulture Fair point! CICO is the mechanism of weight CHANGE but not the whole picture of HEALTH. I eat quality food AND track calories. They're not mutually exclusive.
CICO is like saying "to save money, spend less than you earn." Technically true, but it doesn't tell you HOW to do that, which expenses to cut, or how to earn more. Useful framework, incomplete advice.
I think the value of CICO is as a reality check. If someone claims a diet works through "metabolic magic" and not calorie reduction, they're wrong. CICO keeps us grounded in physics.
Ok I think I get it. CICO is the fundamental rule (like gravity) but there's a lot more to nutrition than just counting calories. Useful to understand but not the whole story. Thanks!
Well summarized. Understand CICO so you know WHY things work. But focus on food quality, satisfaction, and sustainability to make it ACTUALLY work long-term.