Risk of symptomatic gallstones and cholecystectomy after a very-low-calorie diet or low-calorie diet in a commercial weight loss program: 1-year matched cohort study

Abstract

Background:Concern exists regarding gallstones as an adverse event of very-low-calorie diets (VLCDs; <800 kcal per day).Objective:To assess the risk of symptomatic gallstones requiring hospital care and/or cholecystectomy in a commercial weight loss program using VLCD or low-calorie diet (LCD).Design:A 1-year matched cohort study of consecutively enrolled adults in a commercial weight loss program conducted at 28 Swedish centers between 2006 and 2009. A 3-month weight loss phase of VLCD (500 kcal per day) or LCD (1200–1500 kcal per day) was followed by a 9-month weight maintenance phase. Matching (1:1) was performed by age, sex, body mass index, waist circumference and gallstone history (n=3320:3320). Gallstone and cholecystectomy data were retrieved from the Swedish National Patient Register.Results:One-year weight loss was greater in the VLCD than in the LCD group (−11.1 versus −8.1 kg; adjusted difference, −2.8 kg, 95% CI −3.1 to −2.4; P<0.001). During 6361 person–years, 48 and 14 gallstones requiring hospital care occurred in the VLCD and LCD groups, respectively, (152 versus 44/10 000 person–years; hazard ratio, 3.4, 95% CI 1.8–6.3; P<0.001; number-needed-to-harm, 92, 95% CI 63–168; P<0.001). Of the 62 gallstone events, 38 (61%) resulted in cholecystectomy (29 versus 9; hazard ratio, 3.2, 95% CI 1.5–6.8; P=0.003; number-needed-to-harm, 151, 95% CI 94–377; P<0.001). Adjusting for 3-month weight loss attenuated the hazard ratios, but the risk remained higher with VLCD than LCD for gallstones (2.5, 95% CI 1.3–5.1; P=0.009) and became borderline for cholecystectomy (2.2, 95% CI 0.9–5.2; P=0.08).Conclusion:The risk of symptomatic gallstones requiring hospitalization or cholecystectomy, albeit low, was 3-fold greater with VLCD than LCD during the 1-year commercial weight loss program.

Preventing a Mass Disease: The Case of Gallstones Disease. Role and Competence for Family Physicians

“…This is the case in patients starting very-low-calorie diets (i.e., <800 kcal/d) 53) or undergoing bariatric surgery (up to 48% of patients for weight loss exceeding 25% of their original weight). 53,54) The overall risk decreases when body weight stabilizes after approximately 24 months. 53) Weight cycling also represents an independent risk factor for gallstones.…”

“…53,54) The overall risk decreases when body weight stabilizes after approximately 24 months. 53) Weight cycling also represents an independent risk factor for gallstones. 55) Excessive de novo biosynthesis of cholesterol and biliary cholesterol excretion are the two main pathogenic factors.…”

“…52,57) The risk of developing symptomatic gallstones decreases if gallbladder motility is improved by appropriate fat content in the diet (at least 7 g/ d). 53) UDCA, which is litholytic and hydrophilic, greatly decreases the risk of cholesterol gallstone formation (<10%) and of gallstones be-coming symptomatic, 58) following rapid weight loss. 58,59) A meta-analysis of 5 randomized controlled trials including 521 patients (322 taking UDCA and 199 taking a placebo) concluded that UDCA 300-1,200 mg/d effectively prevents gallstone formation after bariatric surgery, 59) reducing the incidence from 32% to 2%, 60) with no severe side effects.…”

Scientific Opinion on the essential composition of total diet replacements for weight control

“…The most commonly proposed mechanisms for gallstone formation during rapid weight loss are supersaturation of bile with cholesterol in combination with an impaired gallbladder emptying as a result of the reduced gallbladder stimulation because of the low fat content of weight loss diets (Johansson et al, 2014). It has been proposed that 5-10 g/day of fat in VLCDs would be sufficient to attenuate the higher risk for gallstone formation associated with rapid weight loss (Festi et al, 2000;SCOOP Taskforce, 2002).…”

“…This is independent of the dietary weight loss strategy used. However, large reductions in body weight may also result in the loss of bone mass and a higher risk of gallstone formation (Berg et al, 2014), the risk of which increases the more rapid the weight loss (Erlinger, 2000;Festi et al, 2000;Johansson et al, 2014). In addition, during energy restriction, several hormonal changes occur, such as a reduction in the concentrations of noradrenaline, triiodothyronine (T3) (but not thyroxine (T4) or thyroid-stimulating hormone (TSH)) and insulin (SCOOP Taskforce, 2002), all of which usually remain within the normal range.…”