IT takes adults an average of 13 days to give up sustainable habits-with ‘meat-free days’ being the first to go, research has discovered.A study of 2, 000 adults found carnivorous Brits usually only manage to ditch their favourite foods for a plant-based diet for 12 days in total.... 1 Using the food waste bin, using eco settings in the home, and only boiling the water required, last for just two weeks Credit: Getty Using eco-friendly products is a behaviour people can keep longest, but even th