not eating enough?

I often tell folks to always take advice from their friends with a grain of salt but if you are not eating enough in this case they are right.

I'm very impressed with your dedication to fitness but if you don't feed your body the right stuff, it will not help you build lean muscle.  If you stop and look at it, that's what toning up really is.  To have a well defined body, you will lose body fat but gain muscle. Recommendation is lots of fruits and veggies, lean protein, fish and whole grain carbohydrates like brown rice etc. 

Always eat a healthy breakfast and eat 4 other small meals through out the day paying special attention to the recommendations above.

Also your kickboxing should provide great cardio, so I would add more days of strength training to really help build lean muscle.

All the best