Plain, instant oatmeal is slightly lower in carbs, with 27 total grams and 23 net grams. Flavored oatmeal can be higher in carbs due to the addition of sugar and fruit.
So, Yes, you can eat oatmeal on a plant based diet. It’s one of the best carb-rich foods you can consume to get your daily fuel. Also, it’s a quick and easy breakfast meal, especially overnight oats. You can also find oats in whole grain muesli if you want to mix things a bit.
Oats are not on the list of low-carb foods. Some low-carb diets will allow you to eat oatmeal even though it is high in carbs. Oatmeal may have benefits for weight loss due to its protein and fiber. Low-Carb Lowdown