Food for Thought — September

Intermittent Fasting: Pros, Cons and Why It’s Not for Everyone
A plate used as a clock to show the intermittent fasting method: sixteen hours diet, eight hours eating time.

This monthly feature was written by Nutrition Sciences Services Practice Manager Kaitlin Poillon and Assistant Clinical Professor and Director of the Center for Nutrition & Performance Nyree Dardarian from Drexel’s nutrition counseling and the Department of Nutrition Services in the College of Nursing & Health Professions.

Intermittent Fasting (IF) has become an increasingly popular fad diet over the past few years. While IF may lead to results such as weight loss, increased cognition and improved overall body composition in the short-term, it is not very sustainable for many interested in making long-term lifestyle changes. There is much more research to be done on IF, especially in the human population, so it is important to get the facts straight.

The Pros of IF

  • It is Easy – There are Few Rules
    • No need to give up your favorite foods or track calories.
    • Pick a new eating schedule and stick to it.
      • Consuming foods only between the hours of 12–8 p.m. is an example of the 16/8 method where one fasts for 16 hours and eats over a period of 8 hours per day only.
    • No Calorie, Protein, or Macronutrient Counting
      • Ditch the tracking apps and food journals! IF is based on the idea that eating only within certain hours of the day will lead to health benefits. No calorie counting is necessary; however, it is crucial to ensure you are consuming enough nutrients, vitamins, minerals, and fluids daily.
    • Weight Loss
      • The wide popularity of IF is most likely contributed to the fact that it leads to weight loss. Many studies also point to fasting in helping individuals lose overall body fat.

The Cons of IF

  • Energy Loss
    • Only eating within certain hours of the day may lead to reduced energy stores, causing increased hunger and fatigue.
  • Overeating
    • It is common for overeating to occur, usually during the after-dinner hours, in those who do not eat consistently throughout the day. If this continues over an extended period, weight gain is likely.
  • Minimal Human Studies
    • The most compelling of studies completed on IF have been done on animals, meaning that the same results may not apply to humans.
    • Research completed in the human population have small sample sizes as well as very specific populations of interest (e.g., overweight individuals with diabetes or well-trained athletes). Therefore, studies on IF in the general population are needed.
  • Not Sustainable Long-Term for Many
    • While one may see quick results with IF, it is an unsustainable lifestyle to partake in long-term for many. Learning to consume balanced, well-portioned meals and snacks on a consistent basis throughout the day to ensure proper energy restoration is the key to prolonged sustainability.
  • Does Not Teach Balanced, Non-Restrictive, Mindful Eating Habits
    • Intermittent Fasting is a form of restrictive eating. Research continually proves that food restriction leads to a binge-eating response later, causing an increase in weight over time.

Overall, it is important to discuss your diet and eating plan with an expert, preferably a Registered Dietitian, to determine what is best for your health. Sign up for a nutrition counseling session at Drexel University today by emailing to learn more.