 [ Symptoms ] can lactose intolerance cause weight gain if all my food rushes through could my body be overdoing calorie retention  if all the food i eat constantly rushes through could my body be overcompensating and desperately trying to get calories out of food because it usually rushes out  i have timed my body before and high lactose items last 15 minutes until desperate release this sounds like the gi may have to be in high gear just to try to absorb food if it is in this gear when i do not have lactose i feel it may be a reason for weigh gain or retention [ Disease ] although its an interesting theory it is not supported by science lactose intolerance does not cause weight gain excess weight occurs when you eat more calories than your body burns in fact people with more serious gastrointestinal problems like ulcerative colitis or crohns have food rush through them and they tend to be underweight and sometimes malnourished the body does not seem to overcompensate