Hi! I am planning to start Krav Maga next month and my purpose is not only self-defense, I also want to lose weight. I am 6'1 and I weight 210 pounds. Would you recommend to start Krav Maga or are Kickboxing, Judo or Karate better Martial Arts to lose weight?
As above, sort your diet to lose some weight. By all means start an art - you'll get some cardio workout, but supplement that too with something else like swimming, gym etc. Krav is great fun but it can be hard to find a good school, and can be a maligned 'art' so you may not get much support for it on here!
Yep, there's a reason that the saying "abs are built in the kitchen" has stuck around... When picking a martial art it's most important to find one that you enjoy, otherwise you won't keep at it. So try out all the clubs near you, see whether you get on with the instructor and see whether the lessons are fun, then do that one with all the enthusiasm you can muster! Also, it gives you a reason to stick to your eating plan
Obviously diet... But I'd reccomend boxing. Obviously you'll have to do extra outside your boxing class. (For the quickest results)
I would suggest that getting to class and getting through the first 6 weeks is the best thing you can do. This will give you the buzz to lose weight and we can then address diet separately.
Boxing because you need to run and run lots to box. You also need to watch what you eat. A good meal plan will be a fist sized portion of protein, a fist sized portion of clean carbs, and lots of raw or steamed veg. Lay off the sugar. Sugar isn't good for you. Unless it's honey or fruits. Lay off the sodas. Or white bread. Or deep fried anything. And get some sleep.
Krav Maga is (supposedly) designed for real life scenarios so the training isn't going to include much exercise. If you want to do Krav anyway, then you're going to need to lift weights and run in your spare time. Taekwondo, wushu, MMA, Muay Thai, kickboxing, and Capoeira will burn the most calories in class. Whatever you do, make sure you eat clean and sleep/drink enough.
Personally I've found that arts with sparring (and a competition element, whether you choose to compete or not) drive you further. When you are sparring rounds you just have to dig deep and keep going, even if that just means moving to limit damage done! I've lost weight without watching my diet too much, ie a balanced one with enough treats to not really count as a diet. TKD in my early 20s was a shock to the system, some classes were practically just circuit training, weight dropped off me and I felt so fit. BJJ in my 40s has been an even bigger shock to the system but less weight drop unless I watch my diet, which I don't. Granted these days, I now need to look into my diet properly to lose weight, but that's age for you.