Feel free to dig into the research there is some to support it and yes I also base it on 26 years of coaching over 1400 people at this point.
“During a fasted state while sleeping, the body relies more on fat stores for energy. When you sleep in a fasted state (such as after an early dinner), your body typically has lower glucose and glycogen levels, which shifts energy usage toward stored fats. This is especially true as the fasted state extends overnight, and the body’s reliance on fat oxidation increases to provide energy for basic functions like breathing, tissue repair, and maintaining core body temperature.
Several studies support this phenomenon:
1. Increased Fat Oxidation During Sleep: Research shows that during prolonged fasting or overnight fasts, the body shifts from using carbohydrates to burning fat. This is due to the depletion of glycogen stores, which forces the body to tap into fat reserves for energy. A study published in The Journal of Clinical Investigation supports the idea that fasting increases lipolysis (fat breakdown) and ketogenesis (production of ketones from fat), which the body can use for fuel during sleep.
2. Hormonal Influence: Hormones like human growth hormone (HGH), which are released during sleep, particularly during deep sleep, promote fat burning. Additionally, the fasting state increases levels of catecholamines (like adrenaline), which further stimulate fat breakdown. According to a review in Nature Reviews Endocrinology, fasting overnight can enhance fat metabolism due to the combined effects of lower insulin and increased levels of HGH.
3. Fasting and Metabolic Flexibility: A study in the American Journal of Physiology suggests that fasting, especially overnight fasting, increases the body’s metabolic flexibility, meaning it becomes more efficient at switching between carbohydrates and fats for energy. This flexibility leads to increased fat oxidation during sleep when in a fasted state.
Thus, when you’re in a fasted state while sleeping, your body does indeed rely more heavily on fat stores for fuel, especially after glycogen stores are depleted from not eating for several hours before sleep .
