Glycemic Index uses.  Glycemic index  is a very popular way of  anticipating  the  "blood sugar rise"  effect after eating certain foods. Different  food sources may have the same number of total calories per portion, but have different "sugar raising effect"  on the same person.  The measure of this rise, as compared to the blood sugar rise caused by pure glucose portion,  is called the Glycemic Index.

You will find a lot  of information in books and on the internet , lists, explanations of Glycemic Index and the related measure, Glycemic Load. Also,  complicated  measures of carbohydrate grams  per weight in grams or per 1 /2 cup serving and  per number of calories. Glycemic index is used most commonly for  diabetic diets and lifestyles  to "painlessly" , without a lot of sacrifice, decrease the  over-all  sugar effect  of the diet.  My experience, and that of my hundreds of weight loss and management patients, is that  "you can't have your  Glycemic Index Cake and eat it too!"

Glycemic index for Weight Loss:  THIS ISSUE is dedicated to weight loss  and weight maintenance warriors. This  program is  geared more towards non-diabetics, and diabetics, who  want to have success in weight loss and management. For those of you who have gone through our weight loss and management program... you know that you can work with  your body to achieve  desired health and weight goals in a sustainable manner....it  just takes understanding your body and  how it is effected by various  foods. Sounds easy enough?

The standard  way of breaking down  foods in  Glycemic index categories,  is into LOW, MEDIUM  and HIGH Glycemic index categories. This way, diabetic patients can anticipate how  blood sugar levels and corresponding insulin requirements will be effected; If pure Glucose portion is ingested then the  Glycemic index( G.I.)  for Glucose is set at  G.I. 100. Most foods generally fall below   100:

• Low G.I.                Under 55
• Medium G.I.         56 to 69
• High G.I.               70 to 100+
•                                                    

We want to use the power of  knowledge of  the  intense, immediate  and varied  effects  that carbohydrates, proteins,  fats and  complex carbohydrates have on our Fat making/Fat burning  biochemistry and hormone messengers. There exists the  exciting ability to control the messages we directly send our body on a daily , hourly basis to MAKE FAT or to BURN FAT! 

Glycemic Load : From clinical experience and  observation over many years, my patients and I have found that  for  effective weight-Loss and weight-management , we need a different way to use the Glycemic index. The Glycemic Load (GL) is a measure which takes account of the Glycemic Index of a food  and the available carbohydrates in the food. Although very useful , these values are not as available or easy to calculate "on the fly"  for weight loss or maintenance  participants. The easiest way to make use of GI from our experience at our Wellness Clinics  for short and intermediate weight  nutritional goals is to subdivide the GI into Very Low Glycemic Index, Low Glycemic index, and  Medium and High Glycemic Index.

• Very Low GI        30 and under
• Low GI                31 to 49
• Med to High GI  50 to 100+

Very Low GI: Any foods above 30 GI, will refexively begin to cause cravings and hunger, increase ups and downs in blood sugar  and insulin. Foods in the Range 50 GI  and above, have an even more dramatic effect on  cravings, hunger,  blood sugar spikes and excess (hyper) insulinemia.  Why stay under the 50 Glycemic Index ? The  labeling of a food as " Medium" GI can lull you into a sense of security.  Weight loss and management patients will quickly tell  you to expect  effects of weight gain, bloating, tiredness and  hunger side-effects  from  Medium to High G.I..., any foods  above Very Low 30 GI  and over 7 to 8 Glycemic Load. ..... judge for yourself,  medium GI foods: Coca-Cola=55-60, Snickers bar=55-60, fruit jam=51, ice cream=50+, potato chips=51-57  These foods may be medium, but anyone can tell they are not conducive to weight loss or weight management. Further  details and  lists of Glycemic Load will be added in a future blog.

         30GI and under                         31 to 49GI                        50+GI....................               

Basically,  staying as much  to the 30& under category ( low GL) will  help with weight loss and maintenance. Straying into the 30 to 50  occasionally, but infrequently,  is  OK on the  a weight maintenance/management  diet.  Avoiding  the 50+ category is IMPERATIVE for weight maintenance and even more for weight loss. The timing of WHAT foods , and WHEN to use them is part of a complete , Physician guided weight-loss and management program.  Results are different from person to person because we are not simple machines that can be placed on a similar regimen to obtain expected results. Clinical experience  has shown that the whole individual must be accounted for and respected to manage  the obstacle course of hormonal changes, metabolic changes, hereditary /genetic  tendencies,  underlying illnesses, sedentary lifestyle, cultural and familial obesity tendencies,  work related limitations, sleep abnormalities and disruptions......on and on. There are a lot of headwinds we  face when attempting to  lose weight and attain a normal BMI  and  percent Body Fat of under 25.

Why the interest in Garcinia cambogia weight loss supplement? Weight loss supplements are more popular than ever. Recently, one has become  very popular after being highlighted on the Dr Oz show.  It was said on that show that Garcinia cambogia extract was the "Holy Grail" of weight loss supplements. Many friends and patients have since asked about  its  safety and efficacy. Like many  Americans  who  have had frustrations and failures  with weight loss challenges,  I too am wary about many new marketing promises that are too good to be true. This includes the parade of weight loss  supplements touted on different media outlets. My wife and I both plead guilty to trotting down to our local GNC after watching a TV episode or infomercial promising weight loss wonders... Then, in a buddy system of wishful thinking, we subsequently  ingest said products on the suggested time-table without  success :  Chitosan, chromium picolinate, CLA (conjugated Linolenic Acid), B12, guar gum, Rasberry ketones, green  tea extract,  Green Coffee bean extract, Kunjac root (lipozene),  Pyruvate, white bean extract, etc. to name a few.  After adding these "weight loss"  supplements to a healthy diet and exercise program, most of the time the only thing lighter was our wallets. So, it is with great "relish" and some skepticism that I invite you to explore Garcinia combogia further...

Background of G. cambogia. Garcinia combogia belongs to a group of  evergreen trees and shrubs that grow in south Asia, Africa and Malaysia.  It is a small to medium size tree that bears  dark green leaves and ovoid red or yellow berry fruit. In local cultures, the fruit, which is the size of a tangerine and looks like a miniature pumpkin, has a thick rind and is used as a condiment and appetite suppressant.The plant yields a sap used for varnish.(1)  The Garcinia combogia which is  most commonly used as weight loss supplement comes from India. The fruit  is called the "Malabar Tamarind' or the "Brindall Berry." 

In Ayurvedic medicine, the Garcinia combogia is used as an emetic and bowel purger in  cases of intestinal parasites. It was also used  in cases on oligomenorrhea when meneses was  delayed. (3) in south Asia, it is also  used for angina.  In veterinary medicine it is used as topical applications for bovine mouth disease.

Extracts of the fruit, particularly the rind,  are often used  as commercial appetite suppressants such as  No-Diet Diet,  Hydroxycut, Bio-Max3000,  Leptoprin,  PhytriMax, XanGo, Lite Bites,  Garcinia Trim plus, Super ProLean Mega Fat Burner, Body busters, Micro-slim, Lipotrol, Citrichrome, Citrilite, Garcinia-max Diet system. (2)   The active ingredient  most commonly quoted is Hydroxycitric Acid, but in the "extract" numerous other substances are included: Hydroxycitric acid, garcinol, Malic acid, polyphenols, carbohydrates of anthocyanins, Citric acid, potent anti-oxidants and Ascorbic acid.

Keep your hands and feet inside the ride at all times...here comes the science part....enjoy the ride. The active ingredient in G. combogia extract is the Hydroxycitric acid (HCA)  which has been found to be a competitive inhibitor of the enzyme ATP-Citrate Lyase which in the cytosol catalyses the conversion of Citrate to Oxaloacetate and Acetyl coenzymeA.  Why is this important? Because Acetyl CoA is  necessary in the synthesis of Fatty acids, cholesterol and triglycerides as well as in the synthesis of acetylcholine in the central nervous system.  (3)

Theoretically, a reduction in AcetylCoA would result in a reduction of Malonyl CoA to produce indirectly the reduction of peripheral fat stores by activating the Carnitine Palmityl Transferase 1 enzyme which is involved in the transfer of long chain fatty acids in the mitochondria for oxidation. Thus, it slows down the production of fats (lipogenisis) by decreasing the production of fatty acids; and it increases the  breakdown of fats (Lipolysis) by increasing oxidation of long chain fatty acids. This ocurrs in a diet where  Carbs (glucose) ingested are  being limited from being converted to fats. (3)

What has been proven  regarding G. cambogia? In literature reviews, it is clear from animal studies that :

• C. gambogia extract with Hydroxycitric acid  causes decreased conversion of glucose to fatty acids.
• HCA ingested by mice confirms the reduction in the synthesis of fatty acids, lipogenisis (production of stored fat),  appetite suppression and weight loss. (2), (3), (4)
• The end result of limiting  the  conversion of carbs to fatty acids, is  an "accumulation" of Glucose in the way of glycogen stores in the muscles and liver.  There they can more readily be used by the body  than fat stores.
• An interesting result of the increased glycogen stores and glucose  will be the effect of producing a  satiety signal and thus appetite suppression similar to Leptin 
• The most clear and reproducible cause of weight loss in the animal studies was loss of appetite, as the mice fed HCA did eat less.(2)
• An increased breakdown of fat is seen with G. cambogia ingestion by way of decrease Malonyl CoA.  Malonyl Coa is an inhibitor of carnitin acyltransferase, which is required for the oxidation (breakdown) of fat. Thus...down AcetylCoA=down MalonylCoA=Up AcylTransferase=Up oxidation of fat=down fat stores
• One last theorized action of HCA , (not proven, nor disproved) is that of increased thermogenisis. Some investigators  have suggested that there is an increase in Brown-fat-like activity where  energy is converted to heat rather than energy. There is no evidence that HCA stimulates this process.

What hasn't been proven regarding G. cambogia? In Human clinical studies on G. combogia extract :

• Although some studies show appetite suppression and weight loss in human trials, most have been conducted on small samples, short term, poorly controlled studies.
• Other randomized, larger, placebo controlled clinical trials have not reported statistically significant weight loss results.
• "Therefore, there is still little evidence to support the potential effectiveness and longterm benefits..." (5) the conclusion of a metanalysis review of  weight loss supplements.
• One key  study  in 1998 JAMA, by Heymsfield et. al in 1998, had 135 subjects randomized controlled trial  for 12 weeks. It is noteworthy in that it showed no significant weight loss results(placebo actually lost more). Of significance, is the investigators chose  to include a low calorie, low carbohydrate, High Fiber diet. (6)
• In general, at recommended doses (3gm G. combogia /day or 1.5gm HCA/day), no studies have shown toxicity, or drug interactions (3), (5) although there are rare reports of lactic acidosis in a diabetic patient. Also, at higher doses  mice studies showed  testicular atrophy.

Does Garcinia cambogia extract work? What are the conclusions we can draw? Yes it works, in very limited fashion. In mice.  Which can  easily be blunted and overcome by dietary, activity and health considerations (variables) in Humans. In the tightly controlled environment of animal testing models, it is clear G.cambogia extract meets our theoretical goals. In the  much less controlled and  unpredictable  arena of  human clinical trials and anectodal use...the results are  all over the map. In the landmark study  by Heymsfield in 1998 the results fell short of our desired goals for a weight loss supplement. Why don't the animal studies translate to predictable human results? Because G. cambogia is not a simple  appetite suppressant , hyper-metabolic- fat burner like some of the popular prescription amphetamine type drugs.

It seems that G. cambogia ONLY  acts as an appetite suppressant AFTER it block glocose(sugar/carb) conversion into fat. G. cambogia inhibits the enzyme  in thet  pathway being, then  the sugar(glucose) builds up as short-term, easily usable glycogen stores in the liver and muscle. Instead of stored in the  more stubborn, difficult to use and "burn" adipose(fat) stores.  So it actually takes  carbohydrate in the  diet and keeps it as available sugar(glycogen), rather than long term fat stores. Once this is done,  the easy access Glycogen stores can be "burned" and depleted by increase in low level, "anaerobic" activity on a frequent basis, rather than  strenuous activity.  Once this is done, the excess sugar/glycogen stores can act as an appetite suppressor. Once this is done, the decreased AcetylCoA leads to increase in fat  oxidation "burning."

The difficulty in this scenario playing out in the 1998 study may be that  the  study participants were placed on low  carbohydrate , High Fiber diet.  And excercise of sufficient frequency and duration was not mandated.

• HCA or C. Cambogia is usualyl taken 1/2 hour to one hour before the primary meals , three times daily.  If the diet was high in fiber, than it is likely that the  supplement taken 30 to 60 minutes prior would have limited absorption in the gut. 
• If the diet is rich in fat and protein calories and low in carbohydrate calories, than the cascade of desired effects caused by blocking an excess of  glucose does not ocurr in sufficient  amounts to suppress appetite or burn fat.
• If we we do not get an excess of glucose being diverted from fat storage to glycogen storage, we do not get appetite suppression.
• If we do not have a drop in Malonyl CoA, we do not have an  increase in the Carnitine pathway and increased "burning" of  fat stores (adipose).
• If we do not have a  structured,  frequent low level activity and negation of a sedantary lifestyle, we do not burn  & deplete the excess glycogen stores.

So with this in mind,  if you were to use C. gambogia (3gm/day) extract  as a primary weight loss supplement  (or HCA 1.5gm/day) , then it could be hypothesized that a low glycemic , yet complex carbohydrate adequate diet (30 to 50%), with lean proteins  and fats could provide the substrate for the enzyme inhibition key divergence point for glucose at ATP Citrate Lyase enzyme. Frequent activity and strength training would  provide a "sink" for the carbs in the glycogen stores surplus which also cause appetite suppression.

IMHO. Dr Nick

References.

1. www. FloraCafe.com
2. "HydroxyCitrate as a weight lossSupplement" Thomas J. Wheeler, Phd, www.Quackwatch.com
3. "Garcinia cambogia" Villar Del Fresno, Angel. Emilia Carretero. Farmacia Profesional.2005 June 19: 70-73
4. "Garcinia cambogia" The merican Journal of Clinical Nutrition. Max H. Putter and Edzaard Ernst. April 2004 v.79 p529-36
5. "G.Cambogia" Critical Review in Food Science Nutrition. F. Marquez, et. al., 2012 Jul. pp52-57
6.  Heymsfield SB,Allison DB, Vaselli JR, Pietrobelli A,Greenfield D, Nunez C. Garcinia cambogia(hydroxycitric acid) as a potential antiobesity agent. JAMA  1998.280: 1596-600