The 12-Hour Intermittent Ketosis Eating Plan

Integrating the Ketogenic Diet with Intermittent Fasting:

I am all for losing weight/fat mass and reducing your percent body fat – especially visceral fat.  The problem is that most people – including myself – have trouble following a rigid diet of any sort.  I, also refuse to count calories – carbohydrate or otherwise – so how can I ask my patients to do it if I won’t.  The diet for life or eating plan for life for me must be effective yet simple.

Previously, we discussed the benefits of intermittent fasting – which I call Intermittent Ketosis.

When fat has already been stored in the body e.g., the belly fat, it is very difficult to shift it – unless the body is in ketosis.  Ketosis occurs when the body has used up its glucose and most of its glycogen.  When this occurs, the body shifts to fat burning for energy and produces ketones (hence the turn ketosis).

Ketones can be used for fuel instead of glucose when the body is burning fat.  This is why the Ketogenic diet can produce impressive fat loss.  The Ketogenic Diet can be great for weight loss, but staying in a chronic ketosis state is NOT optimal or realistic for anybody to follow in the long term.  I would say the same thing about the Paleo Diet and other severe carbohydrate-restrictive diets, by-the-way.

So what is the solution?  I believe that Intermittent Fasting is the way that humans have been physiologically – designed to eat.  I am uncertain whether the 8 – Hour eating window and the 16 hour fast is optimal but it does work in humans as well as animals.  The mechanism is a simple one, I think.  Eating over an 8 hour time period not only restricts the total food intake, it, more importantly, also limits carbohydrate ingestion to 8 hours.  Voluntary Fasting and fasting while we sleep will eventually burn off the glucose and glycogen to the point that the body will automatically shift into fat burning/ketone-producing mode.  If this is the case, we should be able to combine the Ketogenic Diet with Intermittent Fasting relatively easily – since the Ketogenic Diet is already carbohydrate restricted.  It also has a high intake of good fats. For the record, we could also combine it with Paleo or other carbohydrate restriction diet.

What I am proposing is carbohydrate restriction for 16 hours i.e., eating carbs over an 8 hour window and using a Ketogenic eating approach to maintain ketosis for four more hours – for a total of 12 hours.  This also follows the light-dark cycle.

For example, if my carbohydrate eating time was 9 am to 5 p.m., I could eat ketogenically between 7 and 9 a.m. and 5 and 7 p.m.  I could have a ketogenic breakfast after waking up, have my carbs during the day then have a ketogenic dinner to begin the process of entering into ketosis before sleep.  Remember that none of you should be eating anything after 7 p.m.  I think that I will call this the 12-hour Intermittent Keto Diet.

As resources, I am using “The Eight Hour Diet” by David Zinczenko and the “Bulletproof Diet” by Dave Asprey   (The latter book is really close to ideal, since it appears to be a modified ketogenic diet approach that also includes intermittent fasting to a certain extent).  He uses the bulletproof coffee to extend the night fast by about 4 hours in the morning).  Both of these authors are really into research and documentation.

In order to monitor your progress, you should take some initial physical measurements – like chest, waist and hip size, and upper arms.  It is most important to assess your percent body fat and your lean muscle mass. This is most easily accomplished by any BIA or Body Impedance Analysis device.  Many scales have this ability.  Any weight loss must not be from lean muscle.

In summary, then,

  1. For an eating plan to work, it has to be simple, effective and non-depriving. Since we all have to eat, when we eat and what we eat is of paramount primary importance.  We can augment the plan with exercise, mindfulness and stress reduction and so on.
  1. Ketosis is necessary for losing stored fat weight. Remember that weight does not reflect body composition.  You can gain overall weight and lose fat (think bodybuilder) – so don’t obsess over the scale.  Make sure that your lean muscle mass is stable or increasing as your percent body fat and fat mass goes down.
  1. With the 12-Hour Intermittent Ketosis Eating Plan, carbohydrate intake is restricted to an eight hour period. Personally, I have chosen 9 a.m. to 5 p.m. as my 8 hour peiod.  Between  7 a.m. and 9 a.m. and between 5 p.m. and 7 p.m. I will eat ketogenically – if I eat anything at all.
  1. Do not eat anything after 7 p.m.

Until next time,

Dr. G