Before the training
In order to burn fat more effectively during training, it is often not necessary to consume carbohydrates 2-4 hours before endurance training. The best thing to go before the breakfast jog, without a sip of juice or coffee. Nonsense!
Training on an empty stomach is contra-productive!
It is true, however, that the relative fat burning during the training is higher (Horowitz et al. 1997), but then also less. That is, the amount of burnt fat remains the same for 24 hours. Danger during training on sober or hungry stomach is, however, that not only fat is broken, but also muscles (Singh 1998)! And this is absolutely counterproductive to long-term fat reduction.
Sugar makes the workout more effective!
Reading: Tips for increasing Muscles
For the food before the training also speaks that more power can be provided, which leads again to a total higher energy consumption and afterburner effect.
Therefore you should stick to the recommendations of the article Pre-Workout Nutrition!
After training – Burning effect is not lost!
In low-intensity workouts, fat burning during training is relatively high, but there is little after-effects. In the course of training with high intensity the energy consumption after the training is significantly increased. This post-burning effect is also increased (source) despite a subsequent food intake and is only slightly reduced.
Exceptionally, sugar is not converted into fat!
The carbohydrates absorbed after training are not converted into fat because they are used to replenish the energy stores in muscles and liver! The reason for this is the enormously increased absorption capacity of the muscles after the workout. The muscles just lick sugar!
The advantages of a food supply that is as fast as possible are that the faster the stores are filled
The greater the energy potential in the next training! (Zawadzki et al., 1992).
The more protein can be used for muscle building! (Miller et al., 2003)
The faster the regeneration! (Williams et al., 2003)
You will find the exact quantities and the ideal time sequence in the article Post-Workout Nutrition.
Reading: Protein for Body Builders
The diet before and after the workout is for someone who wants to lose weight almost the same as for those of the muscles.
The only difference:
If you are very intensely trained, but do not want to build muscle mass, you should do without the protein shake before training. Decisive for losing weight is the quality of the basic diet on the days when is not trained.