personal trainer james staring advises how to achieve a flat stomach .
says eating carbohydrates after exercise will stop them being stored as fat .
exercises that use more muscle groups will help speed up the metabolism .
writing down how a you feel after food stops you eating mindlessly .
what is my energy level like ?
how full do i feel ?
i have a high energy level/i feel satisfied and not hungry .
i have a moderate energy level/i feel just a bit peckish .
i have no energy/i could easily gnaw off my own arm i 'm so hungry .