If you're hungry, you definitely should eat. The meal template is a minimum, it is okay to eat more. So your meals may be two palm-sized portions of protein, two servings of fat (in addition to oil you cook in), 3 cups of vegetables (possibly with starchy vegetables at each meal). They could even be more than that. Fat is an easy way to increase the caloric density of meals, so adding sauces or dips at meals, and adding avocado and olives as well, and choosing fattier protein options could help. You may have to try some different combinations in to see what helps you feel full at meals and then stay satisfied as long as possible. This article has some tips (it's older and mentions potatoes being off limits, that's no longer the case): https://whole30.com/keeping-weight-whole30/.