A lack of sleep (5.5 hours versus 8.5 hours) compromises weight loss during a calorie-restricted diet by reducing fat loss and increasing lean mass loss, while also intensifying feelings of hunger.

noli's read

This advice is based on a clinical study published in the 'Annals of Internal Medicine' (Arnedt et al., 2010), which is a solid reference in the field of chronobiology and metabolism. The research confirms that sleep deprivation alters hormonal balance, promoting an increase in ghrelin (the hunger hormone) and a reduction in leptin (the satiety hormone), which explains the difficulty in sticking to a diet. It is scientifically recognized that, without sufficient rest, the body becomes less efficient at burning fat and tends to draw more on muscle tissue for energy. The claim is therefore very faithful to the observed clinical results. Although the study focused on a small sample (10 adults), it is supported by broader literature (meta-analyses) showing a consistent correlation between short sleep and altered body composition. This is not an exaggeration, but an accurate spotlight on a key biological mechanism.

the sources

1. 1Spiegel K, Tasali E, Penev P, Van Cauter E. 2004
2. 2Al Khatib HK, Harding SV, Darzi J, Pot GK. 2016