In your Brighton Half Conqueror photo you don't look a lard Arse, so maybe you are just a heavy chap. It would be hard to lose much in 3-4 weeks. You could try organic virgin coconut oil. I add it to my porridge. The fat gives me energy, I can last longer before snacking and it is a type of fat that encourages the body to burn the body fats more efficiently. Google it.
To go sub 1:50 you need 8:23 pace. Visualise running that and crossing the line in sub 1:50. Pick NOW which of the two races is going to be the record breaker. Do the intervals and hills training you did for Brighton. Shave your legs. Buy some ASIC gel racers. Start as far up the front as you dare for a clear start. Shave your legs again and rub some coconut oil on them to slipstream.
Thanks very much.
Have been looking at the DS Racers and they seem grand for a half.
Haven't shaved my legs since I appeared in the Rocky Horror Show but if it's good enough for a sweet transvestite from Transylvania it's good enough for the Wilmslow half!