Cholesterol and heart health benefits<\/p>\n
Varady notes that the weight-loss benefits of fasting can help with \u201clowering metabolic disease risk indicators like blood pressure and cholesterol levels.\u201d A small 2025\u00a0six-month intermittent fasting trial<\/a>\u00a0shows \u201cimprovements in triglycerides and LDL\/non-HDL cholesterol,\u201d says Fontana, who co-authored the study.<\/p>\n These improvements occur, in part, because weight loss reduces visceral (abdominal) fat and decreases the liver\u2019s production of fat-carrying particles that circulate in the bloodstream\u2014both of which positively affect lipid profiles.<\/p>\n Mattson adds another potential mechanism at play for reducing blood pressure: \u201cIntermittent fasting increases the activity of the parasympathetic nervous system,\u201d he says. This branch of the nervous system helps the body relax, digest food, and conserve energy after periods of stress or activity, and greater parasympathetic activity can lower heart rate, reduce vascular resistance, and counteract chronic sympathetic \u201cfight-or-flight\u201d activation that\u2019s associated with hypertension.<\/p>\n Again though, there are caveats. \u201cImproved cholesterol and blood pressure generally only occurs if an individual loses over 5 percent of their body weight and if their blood pressure and cholesterol levels were high before starting the diet,\u201d says Varady.<\/p>\n Blood sugar and diabetes: Real potential and real risks<\/p>\n Research also shows<\/a>\u00a0that fasting can influence glucose regulation. This occurs partly because fasting lowers circulating insulin levels, increases insulin sensitivity, and shifts the body toward greater fat oxidation and ketone production\u2014meaning the body begins burning stored fat for energy instead of relying primarily on glucose from recently eaten carbohydrates.<\/p>\n Mattson says intermittent fasting can also enhance cellular stress resistance, stimulate autophagy\u2014a natural cellular \u201ccleanup\u201d process in which the body breaks down and recycles damaged or unnecessary components\u2014and improve mitochondrial function. Together, these changes may improve glucose regulation and the body\u2019s ability to maintain stable blood sugar and metabolic balance during periods of stress, illness, or dietary changes.<\/p>\n Other\u00a0studies show<\/a>\u00a0additional benefits for people with insulin resistance or type 2 diabetes in particular, including reductions in fasting glucose, lower hemoglobin A1c levels, decreased visceral fat, and, in some cases, reduced need for diabetes medications.<\/p>\n