Complex sentence: Similar conclusion is drawn by other studies where intentional weight loss is found to be associated with slightly increased mortality for healthy individuals and the slightly overweight but not obese, while for those who are obese but otherwise healthy the effect of weight loss is neutral.
Split into simpler sentences: Similar conclusion is drawn by other studies where intentional weight loss is found to be associated with slightly increased mortality for healthy individuals and the slightly overweight but not obese. Intentional weight loss appears to be of benefit only to those classified as unhealthy; for those who are obese but otherwise healthy the effect of weight loss is neutral.