Gallbladder motility and gallstone formation in obese patients following very low calorie diets. Use it (fat) to lose it (well)

Abstract

OBJECTIVE: Dieting obese subjects are at risk of developing gallstones. A gallbladder motor dysfunction could have a pathogenetic role. The principal aim of this study was to evaluate the long term effects of two very low calorie diets differing in fat content on gallbladder emptying and gallstone formation in obese subjects. DESIGN AND SUBJECTS: Gallbladder emptying in response to meals (breakfast, lunch and dinner) in two different diet regimens (3.0 vs 12.2 g of fat/d) was evaluated by ultrasonography in 32 gallstone-free obese patients on different days, before and during (at 45 d intervals) one or two 6-month weight reduction diets (for the ®rst three months: 2.24 MJ (535.2 kcal), 3.0 g fat/d vs 2.415 MJ (577.0 kcal), 12.2 g fat/d; for the second three months, the same low calorie diet of 4.194 MJ (1002 kcal)/d for both groups). In 10 subjects, bile analysis was also performed. RESULTS: Twenty-two (69%) subjects concluded the study, eleven in each group, and a signi®cant weight loss was achieved by all subjects. Gallstones (asymptomatic) developed in 6/11 (54.5%) (P`0.01) of subjects following the lower fat diet, but in none with the higher fat regimen. In the dieters during the ®rst three months (very low calorie phase) the higher fat meals always induced a signi®cantly greater gallbladder emptying than the lower fat meals. The cholesterol saturation index initially increased signi®cantly and then decreased, without difference between the two groups. CONCLUSION: In the obese during rapid weight loss from a very low calorie diet, a relatively high fat intake could prevent gallstone formation, probably by maintaining an adequate gallbladder emptying, which could counterbalance lithogenic mechanisms acting during weight loss.

Weight loss and dropout during a commercial weight-loss program including a very-low-calorie diet, a low-calorie diet, or restricted normal food: observational cohort study

“…Rapid weight loss, whether by VLCD or bariatric surgery, increases the risk of developing gallstones, and clinical recommendations advise physicians to inform patients about this risk (13, 17, 20). Gallstone formation has mainly been associated with VLCDs containing low amounts of fat (∼1 g/d) (21–25), and a higher fat content (12–30 g/d) seems to reduce gallstone formation (26–29). …”

Risk of biliary complications in bariatric surgery

“…Postbariatric modifications include cholesterol hypersaturation of bile (through cholesterol mobilization from fatty tissues enhancing cholesterol crystallization [13]), decreased secretion of biliary acids (caloric restriction), increased mucin production (enhancing crystallization) and last, gallbladder hypomotility [3,[14][15][16] (secondary to decreased cholecystokinin secretion related to the hypocaloric diet, or obesity-related resistance to cholecystokinin, to gastroduodenal exclusion, or due to intraoperative injury to the hepatic branches of the vagus nerves [17]). …”

Effect of Dietary Consumption, Advanced Age and Overweight on the Physical Characteristics of Cholesterol Gallstones and Biliary Lipid Composition in West Algerian Women

“…Equally remarkable is the increased risk of gallstones associated with increasing energy consumption in normal-weight women [7]. However, short-term overconsumption by clinically normal subjects does not seem to be associated with increased cholesterol secretion in the bile [8], in contrast to the patients with gallstones fed a high-energy and protein diet [9]. The aim of this study was to determine the effect of age, overweight and diet on the number and size of cholesterol stones and bile composition in west Algerian women undergoing surgery for cholelithiasis.…”