I start work at 8am eat my breakfast at work and by 9am I'm falling a sleep at my desk I tried switching up my breakfast by cutting out sugar any idea?

OSA, change diet . There could be many reasons. Are you getting enough quality sleep? Do you snore? Are you obese? This could be obstructive sleep apnea or another sleep disorder. Also, perhaps your diet (ie breakfast) needs to be looked at. Are you getting nutritious food with nutrients. I would suggest going over all this with your doctor.