Intermittent Fasting: WHEN we eat is as important as WHAT we eat

Weight Loss is a funny thing.  Science tells us that you must either:  restrict calories to less than your basal metabolism, or expend energy over-and-above your basal metabolism to lose weight.  Caloric restriction has also been linked to a longer life.  The problem is…caloric restriction doesn`t work in the real world for an extended period of time.  Humans are humans and deprivation of calories is simply unsustainable.  First of all, you have to be aware of how many calories you take in i.e., you have to count your calories and you have to have the knowledge of how many calories you burn during daily activities.  I don`t know about you, but this sounds like a lot of work.

Studies have shown that the more rigid your diet plan is, the higher your BMI tends to be – not to mention how depressed you were likely to feel.

We all know that fat – especially visceral fat around our midsections – has the potential to create health problems.  There must be a way to lose that weight in an easier way.

In one of the previous blogs, I mentioned that our bodies have internal Biological Clocks which are involved in hormonal regulation, detoxification AND fat burning.   These Biological Clocks are synchronized to the Light-Dark cycle.  Another way to state this is that the Light-Dark cycle influences the Biological Clocks or circadian rhythms  which in turn regulate hormones, detoxification and fat burning.  It would make sense, then, to pay attention to how our bodies are synchronized to light.

During daylight hours the light enters the eyes and influences energy production  for thinking, movement and so on.  At night it goes into detoxification mode.  In a simple sense, we really shouldn`t be eating after the sun goes down.  After 8 p.m., the body wants to eliminate toxins rather than process more food.  Is it possible that our obesity epidemic is, in part, related to the fact that we have artificial light and tend to eat for too long i.e., beyond sundown?  Yes, it is.

Dr. S. Panda, PhD, from the Salk Institute in La Jolla, California, says that “where there are more lights there is more diabetes”.  His hypothesis is that it is the extension of the day using artificial light over the last 50 years has lead to an artificial extension of our feeding times – contributing to the obesity and diabetes epidemic.

intermittent fasting

Dr. Panda divided mice into two groups:  the first group could eat anything they wanted at any time during 24 hours;  the second group could eat as much as they wanted, but only within an 8-hour time frame.  The study length was 100 days.  The first group gained weight.  The mice who were allowed to eat whatever they wanted, but only during the set period of time (eight hours) lost weight.

When the scientists working on  this project saw the results they were keen to try it out themselves – and the results were the same.  Restricting eating for 8 hours and fasting for 16 produces the same results i.e., intermittent fasting facilitates weight loss.  The reverse is apparently true…the longer we stretch out our eating cycle, the fatter we get.

A study in the American Journal of Clinical Nutrition in 2007 compared two subject groups:

  • The first ate all their calories in three meals spread out over the day;
  • The second practiced intermittent fasting, eating the exact same number of calories but in a restricted 8 – hour time frame.

The second group (IF) had a significant modification of body composition including reductions in fat mass.  Apparently, restricting the time-period during which you eat revs up your metabolism and causes your body to burn more calories throughout the day.

The Beltsville Human Nutrition Research Center found that eating the same number of calories, just in a limited period of time, resulted in a significant modification of body composition, including reductions of fat mass”.

In addition, Scientists at the Intermountain Medical Center in Utah compared blood samples of men after 24 hours of fasting versus men after a day of normal eating.  The level of HBH (Human Growth Hormone) were 20 times higher in the fasted subjects.  This is important because HGH protects lean muscle mass and regulates metabolism.

In the journal Obesity Reviews in 2011, intermittent fasting had the same effect on weight loss and fat loss as cutting calories but was more effective in maintaining muscle mass.

Melatonin, the sleep chemical is also involved somehow. When we use artificial light sources, including our cell phones and laptops at night, there is a hormonal backlash.  Melatonin is suppressed.  When melatonin is suppressed your appetite is stimulated as more ghrelin is made and leptin output is lowered so you don`t feel full.  No melatonin means more munchies.

A 2007 Canadian study found that people who slept only 5 or 6 hours per night increase their likelihood of being overweight by 69% as compared to the 7-8 hours per night sleepers.

Intermittent fasting gives the body a break from using glucose as the major substrate for fuel in the glycolysis cycle.   Restriction of carbohydrates allows the body to switch to fat burning rather than glucose burning.  It is my impression that Intermittent fasting is really Intermittent Ketosis.  Those of us who are carrying more weight around our middle than optimal need to enter this state in order to shift stored fat – especially visceral fat.  It makes sense to me that combining the ketogenic diet with intermittent fasting makes the most sense.

In summary, then….

  • Practice Intermittent Fasting by limiting your food intake to eight hours;
  • Do not eat past 7 p.m. at night and especially no carbohydrates;
  • Do not use your laptop or phone after sundown and especially not before bed;

Perhaps take melatonin as a supplement – if tolerated and under the direction of a health professional.

Dr. G Signature