The most important part is reducing sugar and starch (carbohydrates) intake
https://valhallavitality.com/blog/tirzepatide-vs-semaglutide-which-weight-loss-drug-takes-the-cakeBy giving up these constituent foods, you reduce your sense of hunger and you end up consuming far fewer calories. Now, instead of burning carbohydrates for energy, your body will go after stored fat.
Another benefit of cutting back on carbs is lower insulin levels. Your kidneys will begin to remove excess sodium and water from your body. This will reduce swelling and the excess caused by them.