The No. 1 Reason You Might Not Lose Weight on the CICO Diet

Ever heard of CICO? Though it’s hardly new, it is one of the hottest diets on the internet right now, thanks to online forums like Reddit. CICO stands for “calories in, calories out,” and pushes the idea that to lose weight, all you need to do is eat fewer calories than you burn each day. In other words, you can live off Cheetos and Twinkies and still lose weight as long as you burn them off. For dieters who turn their nose up at salads and fish, it sounds like a dream come true. After all, it takes all the guilt out of food choices and turns weight loss into simple math. Unfortunately, there’s much more to the equation. Here’s what the CICO diet gets drastically wrong.

When it comes to diet, quality matters

While weight loss does, to a large degree, come down to a caloric deficit, there are few major caveats to this rule. First, not all calories are created equal, because foods affect the body differently. For instance, a 400-calorie bagel eaten first thing in the morning spikes your insulin levels and causes a sugar crash a few hours later. Not only will you be dragging, you’ll also be famished—making it harder to adhere to your daily calorie goal. Never mind the fact that carbohydrates also get stored as fat.

Diets do not work all the same

If calories were all that mattered, all diets would work equally well. But different diets with the same calorie goals can lead to different weight loss results. For instance, a 1,500 calorie-a-day Paleo diet doesn’t necessarily yield the same effects as a 1,500 calorie-a-day Ornish diet.

As for low-carb diets (far fewer bagels), which are typically high in protein, you may lose a significant amount of weight then hit a wall and experience trouble meeting your long-term weight loss goals. The culprit? The onset of inflammation due to excess protein.

Why fat is the answer to being thin

If you are looking for a diet with a more favorable metabolic response than a calorie-restricted diet, research shows that a ketogenic diet like Bulletproof (think high-fat, moderate-protein, and low-carbohydrate) is the way to go^[1]. In the absence of carbs, the body learns to use fat as fuel and your weight melts off—no calorie-counting required.

Bulletproof founder Dave Asprey lost 100 pounds more than 10 years ago and has kept it off ever since without counting calories. In fact, in an attempt to prove just how wrong the calorie restriction model of weight loss is, he ate about 4,500 calories per day, including a daily stick of butter. He stopped exercising too. And the weight still came off.

Related: How Ketosis Helps You Lose Weight Through Suppressed Appetite

Calorie restriction tells the body (especially women) that you’re in a famine, which slows down your metabolism in an effort to conserve your body’s fat stores.

Hungry for more proof in the quality-versus-quantity debate? Here is a deep dive read  about a Time Magazine news story and one particular study that reveals quality counts—especially when it comes to macronutrients—like protein, carbs, and fat.

Bottom line: CICO is not the best weight loss strategy

Nutrition experts agree that calorie-counting as a weight loss method is old and outdated. And while it may sound easy and painless, putting quantity ahead of quality leads to energy crashes, hunger pangs, a sluggish metabolism, and, ultimately, a weight loss plateau.