Take in 200g of protein a day and 300g of carbs, cut out all the optional fat (like butter, spreads and sauces)

Make sure your calories from the carbs are from stuff low on the glycemic index (like oatmeal)

Get 6 meals a day with 1 pint of water with each meal, its going to make you a little queezy until you get used to all that liquid.

Do 2 rides a day, each of about 20K and try to keep THR at your optimum for fat burn.

Do your morning ride on an empty stomach (but drink as much water as you like) when you wake up in the morning you are in a carbo depleted state, if you can keep to the THR for fat burn, you will be burning the stuff you dont want from the get go.

For your evening ride, try to time it so that your last meal was at least 3 hours before, this way blood sugar is getting low again. Post workout a small amount of complex carbs and a big protein shake. Try and get more sleep (8+)

The starvation mark is anything below your daily requirement based on your calorie needs for your activity level. You want to get fuel for cycling from your fat reserves, the food you take in should just meet recovery and function needs. This is usually called a negative calorie diet, it is useful for losing fat as yuur body will need to source enery from some place in the even of you not ingesting anything. You have to really take care with the loss of LBM though. This is why its preferable to build up the LMB and that in itself will increase fat burn 24/7