Fasting Tracker

Quick answers

Does intermittent fasting lower cholesterol?

Often a little, mostly through weight loss. But not for everyone, so keep an eye on your numbers

What the trials show

Because so many small trials exist, researchers have started pooling them. An umbrella review brought together 11 meta-analyses covering 130 randomized trials of intermittent fasting. It found improvements in LDL cholesterol, total cholesterol, triglycerides, blood sugar, insulin and blood pressure. But it also found that most of these results rested on low or very low quality evidence, mostly from short trials lasting about three months 1.

When fasting is compared directly with cutting calories every day, the two work about as well as each other for weight and heart risk factors 2. Most of fasting's effect on cholesterol comes from the weight you lose, not from the clock.

Key study

A 10-hour window in metabolic syndrome

  • Pilot study
  • 19 adults
  • 12 weeks

People who usually ate across 14 hours or more kept their meals within 10 hours. Weight, blood pressure and harmful blood fats came down, alongside their usual medication.

Wilkinson et al., Cell Metab 2020

Not everyone's cholesterol falls

Most people see their cholesterol improve or stay the same when they fast and lose weight. But not everyone. In a year-long trial comparing alternate-day fasting with daily calorie cutting, LDL cholesterol, the kind that builds up in arteries, had risen more in the fasting group by the end of the year 3. What you eat in your window matters: a short window filled with fatty meats and pastries won't help your arteries.

If you fast for your cholesterol

  1. Have your cholesterol checked before you start, and again after a few months.
  2. Fill your eating window with balanced meals, not just fewer of them.
  3. Never stop or change cholesterol medication to fit a fast without asking your doctor.

Sources

  1. Patikorn C, Roubal K, Veettil SK, et al. Intermittent Fasting and Obesity-Related Health Outcomes: An Umbrella Review of Meta-analyses of Randomized Clinical Trials. JAMA Netw Open. 2021;4(12):e2139558. doi.org/10.1001/jamanetworkopen.2021.39558
  2. Semnani-Azad Z, Khan TA, Chiavaroli L, et al. Intermittent fasting strategies and their effects on body weight and other cardiometabolic risk factors: systematic review and network meta-analysis of randomised clinical trials. BMJ. 2025;389:e082007. doi.org/10.1136/bmj-2024-082007
  3. Trepanowski JF, Kroeger CM, Barnosky A, et al. Effect of Alternate-Day Fasting on Weight Loss, Weight Maintenance, and Cardioprotection Among Metabolically Healthy Obese Adults: A Randomized Clinical Trial. JAMA Intern Med. 2017;177(7):930-938. doi.org/10.1001/jamainternmed.2017.0936
  4. Wilkinson MJ, Manoogian ENC, Zadourian A, et al. Ten-Hour Time-Restricted Eating Reduces Weight, Blood Pressure, and Atherogenic Lipids in Patients with Metabolic Syndrome. Cell Metab. 2020;31(1):92-104.e5. doi.org/10.1016/j.cmet.2019.11.004
  5. Zhang Z, Zhao H, Tao Z, et al. A National Study Exploring the Association between Fasting Duration and Mortality among the Elderly. Nutrients. 2024;16(13):2018. doi.org/10.3390/nu16132018
  6. Grajower MM, Horne BD. Clinical Management of Intermittent Fasting in Patients with Diabetes Mellitus. Nutrients. 2019;11(4):873. doi.org/10.3390/nu11040873

A note on health

Fasting Tracker is designed for general wellness and is not a medical device. Fasting is not right for everyone. If you are pregnant, diabetic, have a history of eating disorders or take medication, talk to your doctor first, and before any extended fast.