More importantly, the intricate relationships among modifications of nutrition intake, changes in psychological states and physiological changes, such as weight loss, changes in hormone levels (e.g., decreased levels of leptin and increased levels of ghrelin after LCDs) and cardiometabolic health (e.g., blood pressure, blood lipids), bring about difficulties in elucidating how LCDs with extremely low carbohydrate intake would impact anxiety levels or eating behavior. This evidence concerns the gene GHRL and Anxiety.