It’s natural for grandparents to dote on their grandchildren and give them sweet treats whenever they see them. But new research suggests this and other influences could have a negative impact on their grandchildren’s health. For the research, the team from the University of Glasgow analysed 56 different studies which included data from 18 countries, including the UK, US, China and Japan. They focused on the influence of grandparents who were significant in their grandchildren’s lives, but who weren’t necessarily primary caregivers. Three areas of influence were considered: diet and weight, physical activity and smoking. When it came to their grandchildren’s diet and weight, grandparents were found to have an adverse impact, with many studies highlighting how they feed their grandchildren high-sugar or high-fat foods - often in the guise of a treat. The researchers also found that grandchildren were perceived to get too little exercise while under the supervision of their grandparents. However, this did depend on whether the grandparents were physically active themselves or not. Furthermore, smoking around grandchildren became an area of conflict between parents and grandparents, with the latter often smoking while their grandchildren were present, even though they had been asked not to. Talking about the findings of the study, lead researcher Dr Stephanie Chambers said: "While the results of this review are clear that behaviour such as exposure to smoking and regularly treating children increases cancer risks as children grow into adulthood, it is also clear from the evidence that these risks are unintentional. "Given that many parents now rely on grandparents for care, the mixed messages about health that children might be getting is perhaps an important discussion that needs to be had."