Pancreas circadian Timing for oscillation functionality

  GLUCOSE RESPONSE: TIME OF DAY EFFECT  

*N= multiple controlled studies, matched meals.

Blood Glucose (mg/dL) ↑(x-axis) 

morning meal: baseline response 

evening meal: elevated response 

200 

150 

100 

50

0

EVENING  MEAL ~ 195

peak spike +20 to +40% higher 

delta =20-40% increase!! 

MORNING MEAL ~ 100

0  0.5 1.0 1.5 2.0

Time after meal (hours) →(y  axis)

MORNING : 100 units glucose response 

EVENING :120 - 140 units glucose response

∆G(%)= [ (G evening- G morming) ÷ Gmorming ]x 100 

Same food.  Different metabolic outcome .

Chapter 1: Introduction 

Studies measuring identical meals at different times of day consistently show glucose spikes 20 to 40% higher in the evening than in the morning. 

Same food, same digestive system, same person. The difference is not the food. The difference is not portion size, not preparation method, not whether you ate it with butter or without. 

 The difference is a circadian oscillation in insulin sensitivity that peaks in the morning and declines across the day governed by the superismatic nucleus in the hypothalamus amplified by melatonin onset in the evening and executed by clock genes operating inside the insulin producing cells of your pancreas. ( Full details , click here to read on ) 

 THE VARIABLE IS NOT THE FOOD 

🕐🕑🕒🕓🕔🕕🕖🕗🕘🕙🕚🕛

TIME OF DAY 

Then what changes? 

∱(glucose)= ∱ (food, time) 

time is an independent variable 

🍯🍲🍳

FOOD COMPOSITION: identical ❌ ⇍ruled out

DIGESTIVE SYSTEM: same person ❌ ⇍ruled out

BODY: same individual ❌ ⇍ruled out

CONVENTIONAL VIEW: resp ∱(food only) 

→ correction required →

ACTUAL MODEL: resp ∱(food, time) 

 The difference is not the food 

 CONTROLLED VARIABLES: ALL ELIMINATED  

elimination of confounds 

None of these explain the 20-40% glucose difference 

❎ PORTION SIZE: held constant-X eliminated } not the cause 

❎ PREPARATION METHOD: identical-X eliminated}  not the cause 

❎ BUTTER/FAT ADDITION: matched -X eliminated}  not the cause 

❎ CALORIC CONTENT: identical -X eliminated} not the cause 

❎ MACRONUTRIENT RATIO: identical -X eliminated } not the cause 

  TIMING : the only uncontrolled variable 

If A=B=C=D=0, then cause =T (timing) -[process of elimination ]

AM 🍪🍩🍳🍲🍗 🔙 G AM < G PM  🍪🍩🍳🍲🍗PM

 CIRCADIAN INSULIN SENSITIVITY OSCILLATION  

PEAK:~08:00-10:00 

🌞 daytime 

high  

↑

 Insulin Sensitivity (IS) 〰

↓

low

ISmax: glucose cleared rapidly 

maximum insulin sensitivity 

TROUGH: ~20:00-22:00 

minimum insulin sensitivity 

ISmin: glucose clearance impaired  🌙 nighttime 

low 

+ 

06:00 

10:00 

18:00 Time of Day (hours) 

14:00 

22:00 

02:00 

IS(t) = ISpaseline + A:cos(2mi-t/T + φ) 

where T= 24 hours (circadian period) A = amplitude of oscillation = phase offset (~morning peak) 

Insulin sensitivity is not constant - it oscillates on a 24-hour cycle