Hailing from Amsterdam, of all places, Alistair Overeem is something of a giant killer.

One of two fighters to hold an MMA and a kickboxing title at the same time, “The Reem” ended Brock Lesnar’s career in his UFC debut.

And thanks to his crane-kick-to-left-hook-to-ground-and-pound knockout of former UFC champ Andrei Arlovski last night in Rotterdam, he should be fighting for the heavyweight title later this year.

Here, we recall a conversation with him about exercise, house music and the guilty pleasure of fast food.

“There’s a fighter in all of us. We all have our own battles. Some people have more of a warrior inside them than others, though.”

It’s about that time everyone is junking their New Year’s resolutions. Why is it so hard for the average guy to stay in shape?
There’s a lot of ways to get in shape. You really need to do two things: enjoy what you’re doing, but have a goal in mind. If you like to fight or play sports, do that, so it won’t feel like exercising. You should really be active every day. Your body needs it and requires it.

I feel like so many problems from anxiety to obesity are related to people living these sedentary lives their bodies aren’t built for.
Well, the big part is diet. I was born in the UK, raised in Holland and live in the US. People in the West basically live on preservatives, sugar and GMOs. You’re not going to get in shape if you don’t clean up your diet. Cleaning up your diet should be a top priority. It’s not just about looking good, it’s about your health.

What are the worst things people are eating?
Fast food. Everyone loves it. I love it, but you’ve got to keep it to a minimum. It’s the biggest danger out there because it’s so cheap and readily available. I mean, they lure you in as a kid with the toy and keep you as an adult with how cheap it is. But you’re eating poison. It takes so much off of your life not just in years, but in quality, because it makes you sick.

So do people just completely give up these guilty pleasures? I mean you even said that you love fast food.
Even with fast food, there are distinctions to be made. Pizza is usually fast food. But if you go to a good Italian restaurant, it’s delicious and isn’t nearly as bad for you. It can even be healthy. Whatever you like from a fast food place, there’s probably at least a less bad version of it somewhere else. In America, I keep all that stuff to the absolute limit. I mean, the feeling you have ten minutes later… you’re just thinking “I wish I didn’t eat that.”

How far out from a fight do you start getting really strict about what you eat?
Six weeks. If I’m on holiday, I kind of do whatever. I follow the 80-20 rule. 80 percent of the time I’m perfect, 20 percent of the time I’m not. But when I’m in camp, I’m all in.

MMA is huge now. It’s not just huge as a sport, it’s a way a lot of guys are getting into shape. How can they make sure they’re finding the right gym?
You have to visit gyms you see the vibe and you have to look at credentials. Who owns the gym? Do they actually teach? Obviously, if you come to my classes you’re getting top-notch training, but not everyone who owns a gym is that qualified. So you need to look around, see what’s going on when you go in. Some gyms train really hard, but “hard” isn’t always what it’s about. You have to find a place that’s doing what you’re looking for: Do you want to get super technical or do you just want “go go go?” There’s a lot to learn and you have to find your own balance.

What makes a person decide they want to get punched in the face for a living?There’s a fighter in all of us. We all have our own battles. Some people have more of a warrior inside them than others, though. I don’t just mean Ultimate Fighters. I’m talking about myself, soldiers, marines, policemen. I’m talking about people who go out there and have the attitude of “let’s get it on and I want to win.”

Why did you start training?
My brother brought me to the gym when I was 15. From his point of view I needed to defend myself and get some discipline. I hated it at first. I just did it because he made me. I was the smallest one in the group. I had no technique, I was weak. But within two or three years I was dominating everyone else in the class. Coaches really stimulated me to get going. I’m glad that I did it now. It gave me direction and purpose.

How much of your success is training and how much is mentality?
You’re forgetting the third factor, which is genetics. Each one of those is a third. The one percent leftover we can put in the hands of the man upstairs. You need a little bit of luck when you’re in a fight.

What does luck look like in a fight?
It’s an X factor. It can turn the fight around. Luck is weird. It manifests itself in so many different ways. But it can determine outcomes in your favor. Maybe it’s a combination of a bunch of X factors. Either way, you don’t want those factors turned against you. 

You produce your own ring music. How did that start?
I’ve been listening to house music for the last 20 years. I’ve been fighting for the last 18. I always picked my own music, but now I produce it on the side.

What makes for good ring music?
You need to touch the crowd. The crowd needs to respond. They need to get energized. I got booed a lot at my last fight when I first came out. Then the drop fell and the bass hit. All of a sudden, everyone was on my side, going crazy.

Does it ever feel good to get booed?
I don’t care what the audience is doing as long as they’re standing up and getting into it. I don’t have any control over the type of response I get. I just want a response.

No can defend.