Autophagy and metabolic adaptation in tumor degradation: the role of fasting, physical activity, nutraceutical compounds and sleep in cancer regression

Autophagy is a self-digestion process triggered by metabolic stress, providing energy through the degradation of cellular components. During intermittent fasting or caloric restriction, it intensifies systemically and can target cancer cells which rely on abundant resources. Fasting reduces growth factors such as insulin and IGF-1, activating autophagy and sensitizing tumors to apoptosis. Moderate physical activity supports the antitumor effects by improving oxygenation and immune response. Nutraceuticals, such as vitamin D and polyphenols from berries or black grape seeds, enhance tumor suppression. Adequate sleep supports immune surveillance, optimizes metabolic recovery, and may stimulate autophagic processes. This article aims to review the evidence on autophagic-metabolic adaptation in tumor control. The methodology consisted of a narrative review of studies published up to 2025, qualitatively analyzed for mechanisms and effects on tumor regression.