I eat normally no more than 1300 calories a day

I eat no more than 1300 calories a day and have a healthy weight and don't lose weight which i don't really want to, I also do regular high intensity exercise: use weight machines, cardio, isometric exercises ect... But I feel I dont need to eat anymore and im fine with 1 big meal a day including breakfast such as: 2 weetabix. If i continue to do this will there be dangerous effects and symptoms that will occur or not. What will happen in the long term. By the way I look healthy and have an athletic muscular body, so why am i not losing weight due to not eating enough? I also don't want to eat too much, so when im satisfied i don't eat so for e.g. I ate 2 weetabix in the morning, then had fast food which contained: 2 chicken strips and regular fries and I did bout 3.5mph walking for 2 hours while roaming around town, oh yeah i also had a 500ml pepsi. And now im not hungry whatsoever im still full and its been 5 hours.