I think there are no studies yet on this topic (if someone find something I would be happy to read them). Macronutrient needs are simply statistics collected over a big number of people during several years. The real macronutrients need is different between every person, the tables show just averages based on gender / country / age.

In general a diet can influence metabolism and hence altering the need for macronutrients, but the degree of precision required for this argument require a clinic study over thousands of people, by how much a requirment is changed.

One thing is sure, macronutrients needed depend on weight, so if your diet change your weight, you need a different amount of macronutrients. Does your vegan/vegetarian diet alter your weight? then the naive answer to your question would be yes (but in reality it is not a good answer).

As general note, we should also note that each macronutrient can be found in several variants across several foods, some variants are more healty than others. Certain fat types are better (nuts, oils). Certain carbohydrates are really bad (sugar).

According only to macronutrient tables one could simply add as many sugar as wanted to get carbohydrates, but that would not be a good choice.

I think there are no studies yet on this topic (if someone finds something I would be happy to read them). Macronutrient needs are simply statistics collected for a big number of people over several years. The real need of macronutrients is different for every person, the tables just show averages based on gender / country / age.

In general, a diet can influence metabolism and hence alter the need for macronutrients, but to find out the degree to which it does so would require a clinical study with thousands of people.

One thing is sure, macronutrients needed depend on weight, so if your diet change your weight, you need a different amount of macronutrients. Does your vegan/vegetarian diet alter your weight? Then the naive answer to your question would be yes (but in reality it is not a good answer).

As a general note, we should also note that each macronutrient can be found in several variants across several foods with some variants being more healty than others. For example, certain fat types are better - nuts, oils - and certain carbohydrates, such as sugar, are really bad.

According only to macronutrient tables, one could simply add as much sugar as they wanted to get their recommended amount of carbohydrates, but that would not be a good choice.