Understanding Energy Systems and Chrononutrition with Danny Lennon
Danny Lennon

Danny Lennon


Danny is the founder of Sigma Nutrition and the main man behind content creation on the site. Known for hosting the top-ranked podcast Sigma Nutrition Radio, Danny is also a respected educator in the field. He has spoken at conferences and events all over Europe including London, Dublin, Amsterdam and Vienna.

Danny has a master’s degree (MSc.) in Nutritional Sciences from University College Cork, during which time Danny completed his research thesis directly under the world-renowned vitamin D researcher Professor Kevin Cashman.

In addition to that research, Danny took classes in biochemistry, clinical nutrition, micronutrient interactions and physiology. Previous to this Danny also completed a BSc. Degree in Biology and Physics Education and spent a year teaching these subjects.

Danny on Instagram or @dannylennon_sigma


Energy metabolism is one of the basic topics of nutrition that is often misunderstood and misinterpreted. Danny Lennon, MSc. in Nutritional Science, explains energy needs and importance of carbohydrates for athletes and then we dive into fat adaptation, fasted exercise and recovery. Danny then explains chrononutrition and how it affects our health.


  • Circadian misalignment is typical among shift-workers.
  • Internal circadian rhythms play a large role in physiology and overall health.
  • Lifestyle (eating and sleeping pattern) can promote or disrupt circadian rhythms.
  • Disrupted circadian rhythms compromise health and increase the risk of disease.
  • We response differently to food based on the time of the day we eat it.
  • Our insulin sensitivity is higher in the morning hours.
  • Symptoms of circadian misalignment can be similar to a jet-lag. 

Time Stamps:

  • 07:30 Understanding energy systems
  • 13:00 Carbohydrate periodization, performance and physiological adaptations to different 
  • 21:00 Significance of carbohydrate periodization
  • 22:45 Nutrition considerations for mixed sports such as team sports and OCR
  • 27:00 Measures to track your recovery. How to know you are under-recoverring.
  • 29:00 Mental side of under-eating / under fueling, relative energy deficiency, fear of gaining fat
  • 34:00 Disordered eating behavior
  • 38:45 Chrononutrition: How meal timing impacts our health
  • 42:30 When to eat for health? Metabolic implications of circadian eating.
  • 43:30 Insulin sensitivity
  • 47:00 Health effects of circadian misalignment
  • 50:20 The most important things to remember if you want to leave a happy and healthy life
  • 55:00 QUESTION from audience: As a coach, how to best work with people who have a preferred dietary strategy, i.e. keto, paleo, high carb, vegan and it interferes with their goals.