When comparing intermittent fasting (IF) and frequent eating (eating every 2-3 hours), research suggests that intermittent fasting may be more beneficial for improving insulin sensitivity and reducing cravings. Here’s an overview of the evidence:
1. Impact on Insulin Sensitivity
- Intermittent Fasting: Studies show that IF, especially time-restricted eating (TRE), can significantly improve insulin sensitivity. A 2019 study in Cell Metabolism found that a 10-hour TRE window improved insulin sensitivity and reduced fasting insulin levels in individuals with metabolic syndrome compared to those eating over longer periods.
- Frequent Eating: While frequent small meals are often promoted for blood sugar stability, studies suggest they may not improve insulin sensitivity. A 2017 study published in Obesity showed that higher meal frequency did not enhance insulin sensitivity and was actually associated with increased insulin levels, which may elevate the risk of insulin resistance.
2. Effect on Appetite and Cravings
- Intermittent Fasting: IF appears to support appetite control. A 2020 review in Obesity Reviews found that IF reduced hunger and cravings, possibly by stabilizing ghrelin, the “hunger hormone.” These hormonal adaptations may enhance satiety and control.
- Frequent Eating: Conversely, eating every few hours can lead to constant insulin release, potentially heightening hunger. A 2015 study in Physiology & Behavior found that higher meal frequency was linked to increased hunger, likely because the body expects regular food intake, which may reinforce cravings.
3. Clinical Trials Supporting Intermittent Fasting
- Alternate-Day Fasting (ADF): A 2019 randomized controlled trial (RCT) in Obesity showed that ADF significantly reduced insulin resistance among obese participants, with greater improvements in metabolic health compared to daily calorie restriction without increased meal frequency.
- Time-Restricted Feeding (TRF): An early TRF model (7 a.m. to 3 p.m.) tested in a 2018 Diabetes Care study demonstrated improved insulin sensitivity in prediabetic men. Participants who fasted overnight had lower blood glucose and insulin levels, indicating potential benefits for managing insulin resistance.
4. The Takeaway...
The current body of research supports intermittent fasting as a more effective strategy than frequent eating for lowering insulin resistance and reducing cravings. While frequent eating may provide short-term energy stability, it can interfere with insulin regulation and appetite control. Intermittent fasting, through its effects on insulin release and appetite hormones, appears to be a promising approach for individuals seeking to enhance metabolic health and reduce cravings.
References
- Sutton, E.F., et al. (2018). Early Time-Restricted Feeding Improves Insulin Sensitivity, Blood Pressure, and Oxidative Stress Even without Weight Loss in Men with Prediabetes. Cell Metabolism.
- Kahleova, H., et al. (2017). Meal Frequency and Timing Are Associated with Changes in Body Mass Index in Adventist Health Study 2. Obesity.
- Antoni, R., et al. (2020). The Effects of Intermittent Fasting on Appetite and Satiety. Obesity Reviews.
- Cameron, J.D., et al. (2015). Increased meal frequency does not promote greater weight loss and adherence in subjects who were prescribed an 8-week equi-energetic energy-restricted diet. Physiology & Behavior.
- Catenacci, V.A., et al. (2019). A randomized pilot study comparing zero-calorie alternate-day fasting to daily caloric restriction in adults with obesity. Obesity.
- Wilkinson, M.J., et al. (2018). Early Time-Restricted Feeding Improves Insulin Sensitivity and Beta Cell Function in Men with Prediabetes. Diabetes Care.
Intermittent fasting offers a practical approach to improving insulin sensitivity and reducing cravings, backed by growing clinical evidence.
So, how often do YOU think you should eat?