This.
During my lose weight journey, I took either Kopi C Kosong or Latte only. 8~12 ounce per day.
Now 6 month manage to shake off 11kg.

Before this I overweight, every morning 1 large size Cham ice, noon cappuccino, night Chagee. Sugar consumption off the chart.

Of course also cut down on rice and fry/oily food.

But I believe O/C (if can, go for kosong as well) is much healthier than Kopi/Teh itself.