New Delhi, 06 Nov (ANI) : A new study has revealed that exposure to cigarette smoke can actually cause weight gain as secondhand smoke being the biggest reason.People who are in a home with a smoker, particularly children have increased risk of cardiovascular or metabolic problems.Involuntary smoking includes altering systemic sensitivity to insulin and once someone becomes insulin resistant, their body needs more insulin therefore any time you have insulin go up, you have fat being made in the body.