3 years ago, Andrew Huberman said that training fasted will increase the loss of body fat. But in another recent podcast, he said that training fasted or fed does not matter for fat-loss. Which one is the truth?

In earlier discussions, Andrew Huberman suggested that exercising in a fasted state could lead to burning more body fat per unit time than if you had eaten beforehand, particularly when engaging in high-intensity workouts followed by Zone 2 cardio. He emphasized that maintaining low insulin levels is crucial for those aiming to optimize fat oxidation through fasting 1.

However, more recent perspectives have clarified that while training fasted might shift the body's preference to burn more fat as fuel, this doesn’t necessarily translate to greater overall fat loss compared to training in a fed state. Dr. Huberman pointed out that the overall energy expenditure is more pivotal for fat loss, and training either fasted or fed doesn't make a significant difference for total body fat reduction 2.

In summary, while fasted training can alter the fuel mix used during exercise, real-world fat loss largely depends on total energy balance rather than the fasted state alone.