75% Of Your Body Is Water And Not Fat. Our bodies are not mostly composed of fat, they’re mostly composed of water. Therefore, most of the weight changes we see from day to day are water changes, not fat change. A few reasons you see fluctuations on the scale: . ▪️Recent increase in cardio (increases blood volume). This is a biggie, can add up to 5 lbs in some people, just plasma + new red blood cells, & can cause a month-long stall in scale weight. ▪️Recent increase in weight-lifting (sore muscles retain water); eventually there will also be muscle gain, though that is a slower process (weeks) ▪️Any soreness, injury or bruising (causes inflammation = local water retention) ▪️Illness (ditto) ▪️Change in timing of dinner to a later time than usual, and/or addition of a late night snack even if you ate the same total # of daily calories. The timing alone has an effect. Later eating means that the gut will still be holding “gut water” used in the digestive process during the next morning’s weigh-in. Even a 1 hr later dinner time can affect scale weight the next morning ▪️Single unusually large meal within past 5 days – large meals take multiple days to digest, during which not only the meal itself, but also a mass of water equivalent to ~2x the meal’s weight, will all be parked in your gut for digestion. . ▪️Eating more carbs after a period of not having had many carbs (causes liver & muscles to increase glycogen stores; each 1g of glycogen is structurally packaged with 4g water so you end up with water weight) ▪️change in dietary fiber (affects “poop weight”) ▪️change in pooping frequency (obvious reasons) ▪️Recent exposure to heat (hot yoga, exercising in heat) ▪️ Menstrual cycle / birth control – about 1/3 of women have noticeable swings in weight during the week before menstruation / week of menstruation. ▪️increase in sodium intake . In short, trust your calorie deficit. If you are tracking your food accurately and are really eating at a caloric deficit, there is no way NOT to be losing fat. The fat loss is just hidden on the scale by the myriad causes of fluctuations in water & digestive waste.