Share The first meal Susie recommends you add to your lunchtime repertoire is a stuffed avocado with tuna, mayonnaise, chilli flakes and cherry tomatoes: this costs $5 (pictured) 1. Stuffed avocado The first meal Susie recommends you add to your lunchtime repertoire is a stuffed avocado with tuna, mayonnaise, chilli flakes and cherry tomatoes. 'The avocado costs just $3 and I mashed it with a cheap $1 tin of tuna, some mayo and a few cherry tomatoes,' Susie said. The dietitian highlighted a recent study that showed if you have an avocado at lunch, you'll eat less all afternoon. 'The fresh natural wholefoods in this meal will keep you healthy, while the protein will ensure you're fuller for longer,' Susie said.