The Health at Any Size movement, which promotes "body positivity" and de-emphasizes body weight and obesity (among other things), claims that intentionally losing weight increases risk of dying, particularly to cardiovascular disease and particularly when larger amount of weight is lost:
What’s worse is this thin-centric healthcare is not benign. It causes harm. One study showed fat women who intentionally lost at least 15% of their body weight were over two times higher risk of death compared to fat women who remained weight stable.4 Another study found that risk of dying from cardiovascular disease was higher in people who lost weight. That risk increased with more weight lost and the group that lost over 22 pounds was at 3.5 times higher risk of dying from cardiovascular disease compared to the weight stable group.5
They cite a couple of research papers:
- Weight loss from maximum body weight and mortality: the Third National Health and Nutrition Examination Survey Linked Mortality File
- Weight change in older adults and mortality: the Multiethnic Cohort Study
Are their claims valid?