Diana Gariglio-Clelland, a registered dietitian at Balance One Supplements, said her go-to packable lunch is plain, whole milk Greek yoghurt with peanut butter and raw oats stirred in. "I like this meal because it's incredibly filling," she explained. "Greek yoghurt has more protein than regular yoghurt, and the whole milk variety is more satisfying and filing than the nonfat kinds." The peanut butter adds flavour and protein, while the oats give the meal texture and fibre. You can also mix it up by leaving out the peanut butter and adding sliced almonds, berries, cinnamon, or any other tasty toppings you want.