Whether you are obese, fat, or just a big person in general then some martial arts may be better than others. For example, Capoeira, which is a type of dance fighting martial arts, would not be ideal.
The 3 Best Martial Arts for Big Guys
Judo is a great Martial Art that is best for big guys because it involves a lot of throws, joint locks and chokes. If you’re a big guy it’s not ideal to stand around throwing punches and kicks all day like in Boxing, Kickboxing, Taekwondo etc. Judo involves more training on your feet than on the ground, which brings us to the next martial art, Brazilian Jiu Jitsu. Here is a link to more details about the martial art Judo
2. Brazilian jiu jitsu (BJJ)
Brazilian jiu jitsu (often called BJJ) is also a great Martial Art that is best big guys because it is similar to Judo and includes takedowns, throws, sweeps, joint locks, and chokes, which don’t require lots of energy. Similar to Judo it’s meant for the most energy efficient way to quickly win a fight. The difference between the two is that Brazilian Jiu Jitsu focuses more on fighting once you are on the ground, whereas Judo focuses more on fighting on your feet as it’s primary focus is throws. Here is a link to more details about the martial art Brazilian jiu jitsu (BJJ)
Aikido is also one of the best Martial Arts for big guys because it is similar to Judo in that Aikido involves throws. You use your opponent’s energy, their attack momentum against them to engage in a throw and / or joint lock. Here is a link to more details about the martial art Aikido