# RKS: CHECKMATING CARBS LOAD - The Carb-Response Equation Dissected

 

# RKS: CHECKMATING CARBS LOAD

THE CARB-RESPONSE EQUATION DISSECTED

RKS / 2026-2027 / Ser 9 / Blog 5

1st August 2026

PANCREAS - THE MARVEL INSULIN PRODUCER

THE MATHS BEHIND RESPONSES OF INSULIN TO CARBS

Dear Reader,

They truly said: ‘Ignorance is Bliss’ is extracted from a phrase that was coined by in 1742 by English poet Thomas Gray. Diabetes mellitus (DM) is 90% of type 2 variety (T2DM) in which the pancreas-secreted insulin is not working. It only implies that all non-diabetics as well as most T2DM cases have circulating insulin and a responsive pancreas which liberate the same when carbohydrates (carbs in the form of glucose) enter blood. If however there is no tight blood glucose control maintained in diabetics, 4-5% of pancreatic beta cells (producing insulin) start failing each year! 

Glycemic index (GI) has become the talk of the town but more important is the Glycemic Load (GL) as has been discussed in the previous blog of July 2026. This present blog is a longish and mathematically-intense to enlighten how GI of carbs should not concern the non-diabetics or those sans of any risk factor of the disease. It could be challenging to fathom the calculated calculations (factoring GI vs GL) but for those serious about their healthy living, food focusing, but yet desirous to enjoy culinary pleasures, it would make a difference to one’s lifestyle if the compiled medical facts are imbibed rather than sadhu-chela like follow myths regarding GI-dictated carbs consumption preferences.

CARBS

THE CARBS CALCULATION

• Carbs that enter blood is primarily glucose, but also include fructose and galactose (these 3 comprise the monosaccharides).
• Glucose per se constitutes 70-85% of carbs consumed.
• 40-45% of fructose absorbed is converted to glucose before it enters the blood stream.
• Even ~10% of galactose that has entered the intestinal mucosa is also converted to glucose before its gains access to blood.
• Hence, 76-99% of carbs are absorbed in the form of glucose.
• Per meal consumption of carbs in 95-150 gms. 
• After factoring the amount absorbed, and the interconversion of other monosaccharides, the glucose quantity that enters the blood per meal is 57.25-110 gms (i.e. 57,250-1,10,000 mg).

ABSORPTION DYNAMICS

Digestion (breakdown of complex carbs to simplest monosaccharide forms) and absorption (entry of glucose into circulating blood present within wall of intestine) of carbs occur almost simultaneously. More than 80-90% of glucose is absorbed from jejunum (duodenum contributing mere 10-20%) since the jejunal mucosa or mucus membrane (inner lining) has maximum capacity for carbs uptake.

• 0.5 gm glucose per minute (min.) per 30 cms of jejunum length is maximally absorbed.
• Jejunum is 200 to 250 cms (6-8 feet) long.
• Hence, per minute absorption of glucose possible from whole length of jejunum is 3.3 to 4.2 gms (~3.75 gms). 
• The transit time in jejunum is 4 hours i.e. 240 mins.
• Hence, maximum of 1,000 gms glucose can be absorbed per meal from jejunum.
• As per NIN / ICMR (National Institute of Nutrition / Indian Council of Medical Research) 95-150 gms are consumed per meal – hence this GL irrespective of whether it is breakfast, lunch, dinner or snacking, is being adequately dealt with in normoglycemic (nondiabetic) individuals by secreted insulin.

Glucose absorption is completed within 1-4 hours, depending upon the GI of carbs consumed, which is well within the 4-hour period during which chyme (digested food admixed with enzymes) persists in the jejunum. However, if the carbs, especially those with GI values, do escape the jejunum unabsorbed, the ileum can also facilitate their entry into the blood stream albeit at a much lower rate of absorption – even lower than distal (last) part of jejunum.

INSULIN

1 unit (U) [also referred as International Unit (IU)] of insulin secreted from the pancreas equals 1,000 mU/L (milli-units per litre or mIU/L) corresponding concentration in blood. Total insulin released for the day is 45.4 IU in 24 hours and approximately 10.8 IU is released during each major meal. 

BASAL INSULIN

The pancreas release a low, steady baseline level of insulin (roughly 0.25-1.5 IU per hour) during the fasting spells resulting in insulin levels of 2.6-<25 mIU/L. The post-meal higher insulin concentrations in blood reverse back to normal basal range within 2-3 hours.

POST-MEALS INSULIN

It takes 10-15 mins. for the absorbed glucose from jejunum to enter into the blood. Pancreas detect the higher than normal plasma glucose concentrations following meals and promptly release insulin within 1 min. which peaks in 3-5 mins. and lasts for 10 mins. 

The corresponding blood insulin concentrations are:

• Fasting: <25 mIU/mL
• 30 mins post-meal: 30-230 mIU/mL
• 1 hour post-meal: 18-276 mIU/mL
• 2 hours post-meal: 16-166 mIU/mL

If at any point of time the blood glucose concentrations rise by >30 mg/dL there is a spiking of insulin release. Usually 2 spikes of insulin release occur after breakfast and 3 or more such bursts occur after each main meal. This can more than adequately counter the rise in glucose provided the levels remain below 140 mg/dL in non-diabetics or up to 199 mg/dL in T2DM.

GI & INFLUENCE ON INSULIN SECRETION

There are variations in amounts of insulin released depending upon the GI of carbs consumed in food:

• Low GI (<55) carbs consumed: gradual and low-amplitude insulin rise at the rate of 0.3 mIU/min. which peaks between 60 to 120 mins. and matches the blood also glucose peaking at 60-120 mins.
• Medium GI (56-69) carbs consumed: sharp, high-amplitude insulin spike at the rate of 0.6 mIU/min. which peaks between 45 to 90 mins. and is similar to timing of blood glucose peaking at 30-60 mins.
• High GI (>70) carbs consumed: massive, overwhelming release of insulin at the rate of 0.9 mIU/min. which peaks, along with blood glucose at same time, between 30 to 60 mins.

Total insulin released post-meal is 72 mIU, 144 mIU and 216 mIU for low, medium and high GI carbs respectively. Although the enhanced GI values-dependent insulin release is variable from individual to individual, the bottom line is the marvel pancreas is geared to release more insulin if GI values of carbs consumed is higher since the speed of these absorbed is greater as compared to lower GI carbs.

GI DETERMINED CARBS ABSORPTION vs INSULIN CARBS DISPOSAL & MAINTAINING NORMOGLYCEMIA

CONCLUSION

The Continuous Glucose Monitoring (CGM) device usage has become a fad and a habit to boast even by non-diabetics to reassure themselves and even proclaim their health consciousness. Blood sugar after meals is medically widely documented to rise to 140 mg/dL in non-diabetics and upto 180 mg/dL in those suffering from diabetes. However, in both cases, the levels will become normal by virtue of the pancreatic insulin response within 2-3 hours. If it takes longer in diabetics the treatment regime is to be re-visited rather than blame a food item consumed! It is alarming to note that, forget the layman, even qualified doctors check their blood glucose levels immediately after consuming any meal or snack although the carbs present in the consumed food item are bound to keep the sugar levels higher than normal for 2-3 hours and this is a physiological reality! 

This blog is indeed medically and could be a self-defeating exercise in trying to fathom it by most laypeople. However, there is sincere hoping that each can focus more on enjoying the culinary pleasures but at the same time keeping sugars within tight control - both fasting as well as after food - by rigorous adherence to individually optimised treatment regimens which should aim to mimic blood glucose readings akin to a normal human being and not necessarily as per set guidelines.

Hoping that the medial professionals and para-medics do fathom the in-depth detailing of the physiology of carbs' absorption and its disposal equation.

DR R K SANGHAVI

Prophesied Enabler

Experience & Expertise: Clinician & Healthcare Industry Adviser

-------------------------------------------------------------------------------------

POWERED BY -

# fuzionnutra.com