The only non-surgical way of doing is to turn on fat burning regime of your organism.
1g of fat equals 9 calories.
Running whole f*cking marathon to burn only 300 grams of your body fat?!
The most effective and optimal healthy way of doing that is FASTING.
Periods of dietary energy restriction sufficient to cause depletion of liver glycogen stores trigger a metabolic switch toward use of fatty acids and ketones.