I decided a few days ago to follow Lyle McDonald’s version of a Protein Sparing Modified Fast (PSMF) (as detailed in The Rapid Fat Loss Handbook). This diet is designed to “spare protein” — that is, loss of lean body mass–by giving an adequate amount of calories from protein, plus 10 grams daily of omega 3 fats through fish oils, plus nonstarchy veggies. Versions of PSMF programs seem to be used a lot for safe rapid fat loss among obese people (which I qualify as). There are a number of references at PubMed to therapeutic use of PSMF diets.
When I decided to embark on it, I’d forgotten all about the relationship between rapid weight loss & gall bladder issues — in spite of having had some rather nasty gall bladder attacks 10 years ago after fairly rapid weight loss (due to loss of appetite from grief & stress about a personal situation). One of those attacks even resulted in my being taken to the emergency room, mostly because one of my coworkers thought it might be a heart attack. An ultrasound the following day found I had no gallstones (possibly I passed one) but my gall bladder was larger than usual.
In any case, I did a bit of research at the time, & opted against a gall bladder removal, for which I’m glad. But my doctor told me to eat “low fat” which seems to be the standard medical advice. Now I think that rather the opposite is true — that low-fat diets (at least the extreme ones) are at least part of what sets one up for gall bladder attacks. Turns out that one of the fundamental issues with gall bladder health is eating enough dietary fat so that your gall bladder empties.
The short version of what I’ve just researched in the last couple days: if you’re going on a rapid weight loss diet or will be undergoing gastric bypass surgery or some other bariatric surgery which will have the same effect, make sure that you are eating at least 10 grams of healthy dietary fats a day to reduce your risk of gall stones.
Now here’s the long version:
Turns out that there is a really really high percentage of gastric bypass patients who get gallstones or sludge in the gall bladder (which can also lead to gall bladder attacks). See, for example:
- Shiffman, et al. Gallstone formation after rapid weight loss: a prospective study in patients undergoing gastric bypass surgery for treatment of morbid obesity. Am J Gastroenterol. 1991 Aug;86(8):1000-5.
- Al-Jiffry, et al. Changes in gallbladder motility and gallstone formation following laparoscopic gastric banding for morbid obesity. Can J Gastroenterol. 2003 Mar;17(3):169-74.
From a little research, it seems one of the biggest contributor to gall bladder issues is low fat diets which prevent gall bladder emptying. In a blog post called “Oh the gall of it”, Mary Eades (wife of & coauthor with Michael Eades of the low-carb diet Protein Power), criticizing the laughable notice that low-fat diets prevent gall bladder disease, explains:
What makes the gall bladder empty? As any basic human physiology text will you, it’s fat entering the first portion of the small intestine. When saturated, monounsaturated, or even polyunsaturated fat reaches this area, its entry triggers the release of cholecystokinin (CCK) which is the hormone that causes the gall bladder to squeeze and squirt bile into the intestine to emulsify the fat.
This is what the gall bladder is supposed to do, for crying out loud; it’s its raison d’etre.
Basically, if you eat hardly any dietary fats, your gall bladder sits around doing nothing, & gets sludgy from bile that never gets do to its job & just sits there getting blechy. Inactive gall bladders are also more likely to form gallstones. Then, if you do eat a meal high in dietary fat, boom! gall bladder attack. All the g.b. attacks I had in 1998 were immediately after eating a high fat meal (Wendy’s burgers in one case, a crapload of M&Ms in another), after having lost a lot of weight during my aforementioned Official Grief & Dumbfoundedness Weight Loss Diet. The medical advice I got at the time was to eat a very low fat diet. Thank gods I learned differently later down the road.
Since the PSMF diet I’m following includes 10 grams daily of omega 3 fatty acids distributed among the meals throughout the day, as well as whatever amounts of fat come packaged with the protein foods I’m eating, I should be okay. Some of the studies at PubMed indicate the low calorie diets that include fat are successful at preventing gall bladder problems; but low fat (say, less than 10 g/day) dieters are much more likely to develop gallstones.
Another strike against ultra low-fat dieting.
Some of the studies showing this:
- Festi D, et al. Gallbladder motility and gallstone formation in obese patients following very low calorie diets. Use it (fat) to lose it (well). Int J Obes Relat Metab Disord. 1998 Jun;22(6):592-600.
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.
In this case, “relatively high fat intake” involved daily 12 grams of dietary fat (108 calories) on a 577 calorie diet during the first three months of the diet. By comparison, the people on the low-fat diet were eating 3 grams of fat (27 calories) on a 535.2 calorie diet for the first three months. Both groups had higher calorie diets for the second three months. 54.5% of the low fat dieters developed (nonsymptomatic) gallstones; none of the higher fat dieters did.
- Festi, et al. Review: low caloric intake and gall-bladder motor function. Ailment Pharmacol Ther 2000: 14 (Suppl. 2): 51—53.
A threshold quantity of fat (10 g) has been documented to obtain efficient gall-bladder emptying…. Adequate fat content of the VLCD [very low calorie diet] may prevent gallstone formation, maintaining adequate motility and may be more economic and physiologically acceptable than administration of an pharmacalogical agent.
This appears to be based on the same study as the prior document.
- Gebhard, et al. The role of gallbladder emptying in gallstone formation during diet-induced rapid weight loss. Hepatology. 1996 Sep;24(3):544-8.
The findings suggest that gallstone risk during rapid weight loss may be reduced by maintenance of gallbladder emptying with a small amount of dietary fat. Ultimately, weight loss reduced bile cholesterol saturation and improved highdensity lipoprotein (HDL) levels.But it’s not foolproof. This study showed lower levels of gallstone formation for people on 30 g/day of fat than for 16 g/day of fat on liquid 900 cal/day diets, but a few people on each diet developed gallstones over 13 weeks on the diet.
- Vezina, et al. “Similarity in gallstone formation from 900 kcal/day diets containing 16 g vs 30 g of daily fat: evidence that fat restriction is not the main culprit of cholelithiasis during rapid weight reduction.” Dig Dis Sci. 1998 Mar;43(3):554-61.
Substantial fat for rapid weight-reducing diets resulted in gallstone formation. Since experiments have shown that our higher fat diet, containing 10 g fat per meal, results in maximal gallbladder emptying, cholelithiasis from rapid weight loss may not be solely attributable to gallbladder stasis.
So something else was also going on. Might it have to do also with pre-diet nutrition? I.e., maybe those who formed gallstones had low-fat diets prior to this diet… just speculating here. Mary Eades ties gall bladder disease squarely to insulin resistance, so maybe it has something to do with that.