Friday, November 23, 2007

Is it really important to do the follow-up visits after bariatric surgery?

After weight loss surgery (let's say gastric bypass or Lap Band), the majority of patients will initially lose some of their excess weight very well. In fact, they may do so well that they take for granted their weight loss trend, and some become less and less compliant with their follow-ups. Does it make a difference? Should patients do their follow-ups with their bariatric surgery programs, in addition to the usual check-ups with their own family doctors? We always felt that patients benefit tremendously from being committed to their long-term follow-ups. Is there any evidecne that long-term follow-ups make any difference? A study is published in the Nov-Dec 2007 issue of the journal "Surgery for Obesity and Related Diseases" titled "Impact of routine and long-term follow-up on weight loss after laparoscopic gastric bypass". It is another addition to a mounting evidence. The authors, (Gould JC, Beverstein G, Reinhardt S, Garren MJ) from the University of Wisconsin School of Medicine, Madison, Wisconsin, looked into the data of patients with 3-4 years of follow-up data after laparoscopic gastric bypass. The patients were divided into 3 groups:

Group 1 patients: had attended every scheduled postoperative appointment
Group 2 patients had attended every appointment for 1 year, then were lost to follow-up
Group 3 patients had been lost to follow-up before 1 year.

Although the excess weight loss (EWL) did not differ at 1 year of follow-up, a significant difference in the EWL was observed at 3-4 years (74% for Group 1; 61% for Group 2; 56% for Group 3). The authors found that the most common explanation for missed follow-up appointments was a lack of insurance coverage. They concluded that on-going, multidisciplinary care is likely a critical component in maintaining the benefit after surgery.

Source Article:
Gould JC, Beverstein G, Reinhardt S, Garren MJ. Impact of routine and long-term follow-up on weight loss after laparoscopic gastric bypass. Surg Obes Relat Dis. 2007 Nov-Dec;3(6):627-30. PMID: 17950045 (Abstract)

Other References:

Shen R, Dugay G, Rajaram K, Cabrera I, Siegel N, Ren CJ. Impact of patient follow-up on weight loss after bariatric surgery. Obes Surg. 2004 Apr;14(4):514-9. PMID: 15130229 (Abstract)

Harper J, Madan AK, Ternovits CA, Tichansky DS. What happens to patients who do not follow-up after bariatric surgery? Am Surg. 2007 Feb;73(2):181-4. PMID: 17305299 (Abstract)

"Surgery for Obesity and Related Diseases" (SOARD) is the official journal of the American Society for Metabolic and Bariatric Surgery (ASMBS) and the Brazilian Society for Bariatric Surgery (SBCBM - Sociedade Brasileira de Cirurgia Bariátrica e Metabólica).

Obesity surgery" is the official journal of several international societies including, among many others, the International Federation for the Surgery of Obesity (IFSO) , the Obesity Surgery Society of Australia and New Zealand and the French Society for Obesity Surgery (Société Française de Chirurgie de l'Obésité)

Saturday, November 17, 2007

Obesity Among Friends, Spouses, Siblings and Neighbors

Obesity has become an epidemic. Right? We hear this all the time. Well, isn't the term "epidemic" used often for diseases that are spread from a person to a person, like infectious diseases? Could the phenomenon of the prevalence of obesity be actually behaving as an infectious process? Could the benefits of obesity control, likewise, spread in an epidemic (good) way? Should the treatment of obesity be considered not only a form of individual therapy, but also, and probably more importantly, a treatment of public health proportions and general community benefits?

A very important article appeared in the July 26, 2007 issue of the New England Journal of Medicine "The Spread of Obesity in a Large Social Network over 32 Years" by Drs. Nicholas A. Christakis and James H. Fowler from Harvard Medical School, Boston and University of California, San Diego, San Diego. The researchers analyzed the nature and extent of the person-to-person spread of obesity as a possible factor contributing to the obesity epidemic. To do so, they evaluated a social network of 12,067 people assessed repeatedly from 1971 to 2003 as part of the Framingham Heart Study.(1) They examined whether weight gain in one person was associated with weight gain in his or her friends, siblings, spouse, and neighbors.

What they found? A person's chances of becoming obese increased by 57% if he or she had a friend who became obese. The type of friendship appeared to be important. Between mutual friends, a person's risk of obesity increased by 171% if the other became obese. In contrast, the influence did not appear to be statistically significant when one person, but not the other, defined the relationship as a friendship. The sex also appeared to be important. When analysis singled out same-sex friendships, the probability of obesity in a person increased by 71% if the friend became obese. For friends of the opposite sex, however, the probablity of obesity did not increase significantly. Among friends of the same sex, a man had a 100% increase in the chance of becoming obese if his male friend became obese, whereas the female-to-female spread of obesity was not as significant.

How about siblings? If one sibling became obese, the other's chance of becoming obese increased by 40%. As for married couples, if one spouse became obese, the likelihood that the other spouse would become obese increased by 37%. By the way, those effects were not seen among neighbors.

If social networks are so influential in the spread of obesity, then this may actually explain another well-known observation. Individuals in weight loss programs or after weight loss (bariatric) surgery, who attend regular support group activities, that modify the person's social network, are more successful than those that do not.

This is a great study that will certainly be quoted over and over in the future.

(1) The Framingham Heart Study is an ambitious project that was initiated in 1948, when 5209 people were enrolled in the original cohort. The Framingham Offspring Study began in 1971, when most of the children of members of the original cohort and their spouses were enrolled in the offspring cohort. In 2002, the third-generation cohort, consisting of 4095 children of the offspring cohort, was initiated. All participants undergo physical examinations (including measurements of height and weight) and complete written questionnaires at regular intervals.


Christakis NA, Fowler JH. The spread of obesity in a large social network over 32 years. N Engl J Med. 2007 Jul 26;357(4):370-9. [PMID: 17652652]

Sunday, November 11, 2007

Excess Fat, Red Meat, Alcohol, and Cancer

"Food, Nutrition and the Prevention of Cancer: a global perspective", a report produced by the World Cancer Research Fund together with the American Institute for Cancer Research , has been the most authoritative source on food, nutrition, and cancer prevention for 10 years. In October 2007, the updated Report was released in Washington, DC. The Report is the result of a five-year process that included examination of the world's literature by a panel of the world's leading scientists, supported by observers from United Nations and other international organisations

The Report found out that carrying excess body fat increases the risk for cancer of the colon, kidney, esophagus, pancreas, and endometrium, as well as breast cancer in post-menopausal women. Their first recommendation is: Be as lean as possible within the normal range of body weight.

The Report also indicated that there is convincing evidence linking consumption of red meats like beef, pork and lamb to colorectal cancer. The recommendation is: Limit intake of red meat and avoid processed meat. People who eat red meat to consume less than 500 g (18 oz) a week, very little if any to be processed. ‘Red meat’ refers to beef, pork, lamb, and goat from domesticated animals including that contained in processed foods. "Processed meat" refers to meat preserved by smoking, curing or salting, oraddition of chemical preservatives, including that contained in processed foods.

Another recommendation: Limit alcoholic drinks. The evidence on cancer justified a recommendation not to drink alcoholic drinks. The report specified that, based solely on the evidence on cancer, even small amounts of alcoholic drinks should be avoided. But, because other evidence shows that modest amounts of alcoholic drinks are likely to reduce the risk of coronary heart disease, the Report recommended limiting rather than avoiding, alcohol consumption.

The strongest evidence on methods of food preservation, processing, and preparation showed that salt and salt-preserved foods are probably a cause of stomach cancer.

The World Cancer Research Fund global network consists of the following charitable organisations: The American Institute for Cancer Research (AICR); World Cancer Research Fund (WCRF UK); Wereld Kanker Onderzoek Fonds (WCRF NL); World Cancer Research Fund Hong Kong (WCRF HK);Fonds Mondial de Recherche contre le Cancer (FMRC FR) and the umbrella association, World Cancer Research Fund International (WCRF International)
The World Cancer Research Fund global network funds research on the relationship of nutrition, physical activity and weight management to cancer risk, interprets the accumulated scientific literature in the field, and educates people about choices they can make to reduce their chances of developing cancer.

An abbreviated version of the full Report

For a summary of the recommendations:

Saturday, November 10, 2007

Hungry, Satisfied, or Full?

For the sake of simplicity and to make points clearer, I will use definitions that may be different from the standard broad dictionary definitions:

Hunger: The unpleasant feeling that accompanies a real physical need for nourishment or food.
Fullness: The feeling that maximum capacity to eat has been reached.
Satiety: A state of satisfaction that can be reached when not hungry, but before feeling full.

When we are hungry, we know it. Of course we need to eat. The trick is either not let yourself get really very hungry, so that you can avoid over-eating, or simply develop the habit of recognizing a point of satiety, or satisfaction, before actually feeling full. Remind you, I am using the definitions outlined above. So, how to recognize that point of satisfaction? Well, that point can be appreciated by allowing your brain to recognize that you are not hungry anymore. The signal will come up, but you have to give it time to reach up there. What that means? Don't eat too fast. Do not enter in your mouth one large bite at a time. Once in your mouth, take your time chewing your food. Enjoy the taste of the food. Chew 20 times before actually swallowing. After swallowing the well-chewed bite, wait a little bit before you get the next bite into your mouth.

If you are using portion control (for example, after weight loss surgery, or as a part of dieting), put on your plate only the portion that you are supposed to eat. If there is more on your plate, do not clear your plate. Eat slowly as described above, till you have almost completed your portion, then STOP. Even if you are not satisfied, stop. Distract yourself. Do something. Then ask yourself in 10 minutes or so: "Am I still hungry? Or do I want to eat just because? If you are not truly hungry, and if you reached the portion size that you have decided, you have probably reached the point of satisfaction and hopefully the above techniques gave your brain enough time to appreciate that signal. Remember, feeling full (using the definition that I wrote above) is not a good signal to stop eating. It is too late. And if you had Lap Band, gastric bypass, or a sleeve gastrectomy, you are probably setting yourself up for a stretch of the pouch. In case of an adjustable gastric band in particular (like the Lap Band), stretching the pouch may be a factor in slippage (prolapse). So, be careful, and stay healthy!