When it comes to weight loss, many people want to know what the best diet is. However, growing research shows that when you eat may be just as important to your health and weight as what you eat. The importance of when we eat is tied to our internal 24-hour biological timing system, called the circadian system.
Circadian rhythms are driven by a master clock in the brain and other clocks throughout the body. These rhythms help regulate sleep-wake cycles, hormones, and metabolic processes. While light and dark are the main cues for the clock in the brain, food is an important cue for clocks in other body tissues. (https://www.aicr.org/).
On the circadian rhythm diet, you eat during a 12-hour window—usually between 7 a.m. and 7 p.m. and 7 p.m. – and fast the remaining 12 hours. Meal sizes are reversed, with breakfast the largest meal of the day and dinner the smallest. This program suggests eating when it makes the most sense given the daily hair removal and reduction of various hormones such as cortisol, insulin and leptin. “It is now becoming clear that circadian disruption increases the incidence and severity of many diseases, including cardiovascular disease and type 2 diabetes.” ()
Factors that can alter the circadian rhythm
For some it is challenging to follow a circadian rhythm diet and your lifestyle needs and internal clock collide. This can happen because of:
- working overnight or after-hours shifts that conflict with natural light and the dark hours of the day
- shift work with irregular hours
- travel that spans one or more different time zones
- a lifestyle that encourages late-night hours or early-morning waking hours
- Medicines
- Stress
- mental health conditions such as brain damage, dementia, head injuries or blindness;
- bad sleep habits — you don’t have a regular sleep schedule, you eat or drink late at night.
How the Circadian Rhythm Diet Works
Research shows that circadian rhythm fasting exercise can promote weight loss in several ways:
- Reduced calorie intake: Although circadian fasting people can eat as much food as they want, they often consume fewer calories. It was found that people who stayed on a time-restricted eating plan unintentionally consumed 20% fewer calories than usual.
- Decreased appetite: People who are overweight or obese experience a decrease in appetite when they practice timely eating with limited time. This decrease in appetite may be due to the timing of eating with certain hormones released by the body.
- Improved metabolism: By aligning meal times with the circadian rhythm, a person can optimize their metabolism. Meals are consumed at times when hormones associated with eating, such as ghrelin and adiponectin, are at their peak. These strategic meal times mean that food will be digested and metabolized more efficiently and less likely to be stored as adipose tissue.
In a healthy person, cortisol (the stress hormone) levels peak around 8am, giving us a jolt of energy to wake us up (in theory). These levels drop to their lowest point at 3am the following day, before rising back to their peak five hours later at 8am again. Ideally, that 8 a.m. peak. will be triggered by exposure to sunlight, if not an alarm. When this happens, the adrenal glands and brain will start pumping adrenaline.
By mid-morning, cortisol levels begin to drop, while adrenaline (for energy) and serotonin (a mood stabilizer) continue to rise. At midday, metabolism and core body temperature increase, making us hungry and ready to eat.
Risks
This way of eating may not be the best choice for everyone, such as:
- Elderly with reduced metabolism
- People who are underweight or have a lower average weight
- People who have experienced an eating disorder
See a doctor if you experience prolonged difficulty realigning with your circadian rhythm.
Denial of responsibility
The Content is not intended to be a substitute for professional medical advice, diagnosis or treatment. Always seek the advice of your doctor or other qualified health care provider with any questions you may have about a medical condition.
