Why am I gaining weight on 1,200 calories?

Almost always because the true intake is higher than the log, or because the scale is showing water. In a well-known 1992 study, people who said they couldn’t lose on under 1,200 calories a day were eating nearly twice what they wrote down. Their metabolism was normal for their size. The fix is in the counting, and that part you can change.

It feels impossible, and it’s easy to conclude that your body is broken. That was the test in the study. It found the bodies worked fine.

The study

Researchers took 224 people starting obesity treatment and studied 10 of them closely: 9 women and 1 man who said they ate under 1,200 calories a day and still didn’t lose. For 14 days they measured what these people burned and what they really ate.

• Their burn was within 5% of what their body size predicted.
• They had under-reported their food by 47% and over-reported their exercise by 51%.
• They had no unusual psychological traits, the authors found.

This isn’t rare. In a 2003 study of 484 adults, people under-reported their calories by 12 to 20% even on a careful 24-hour recall.

The simple version

Think of small charges on a card. Each one is easy to forget. The statement still adds them all up.

Water hides fat loss

Stored carbohydrate is held with 3 to 4 times its weight in water, so a carb-heavy day can put water on the scale that has nothing to do with fat. In a 2014 study of 80 adults who weighed in daily, weight was highest on Sunday and Monday and fell through the week. A single morning can look like a gain when the trend is down.

What to do

• Weigh your food for a week, everything, including oil, drinks and tastes. In Gyroscope, Food XRAY estimates calories, macros and micronutrients from a photo of your meal.
• Judge by the four-week trend of morning weigh-ins, on the real TDEE calculator.
• If careful weighing still shows a gain, see a doctor about other causes, medicines included.