Losing weight without rearranging your gut anatomy has benefits beyond just the lack of surgical risk.
The surgical community opposes the interpretation of bariatric surgery as internalizing jawbones and cutting out healthy organs just to manipulate people’s behavior. They even renamed it “metabolic surgery,” suggesting that the anatomical rearrangement causes changes in digestive hormones that provide unique physical benefits. As proof, they point to the amazing remission rates of type 2 diabetes.
After bariatric surgery, about 50% of obese people with diabetes and 75% of “obese” people with diabetes are in remission, meaning they have normal blood sugar levels on a regular diet without diabetes medication. Normalization of blood sugar can occur within days after surgery. And 15 years after surgery, 30% remained diabetes-free, compared to a remission rate of 7% in the non-surgery control group. Are we sure it was surgery, though?
One of the most challenging parts of bariatric surgery is the liver lift. Since obese people tend to have large, fatty livers, there is a risk of liver damage and bleeding. Liver enlargement is one of the most common reasons that a rare laparoscopic surgery can turn into a completely open surgery, leaving the patient with a large abdominal scar, and an increased risk of wound infection, complications, and recovery time. But even if you lose only 5% of your body weight, your fatty liver may shrink by 10%. That is why those waiting for bariatric surgery are put on a diet. After surgery, patients are usually placed on a very low-calorie liquid diet for weeks. Did their improvement in blood sugar levels come from calorie restriction, rather than some kind of metabolic surgery magic? The researchers decided to test it.
At the bariatric surgery clinic at the University of Texas, patients with type 2 diabetes scheduled for gastric bypass volunteered to stay in the hospital for 10 days to follow the same very low-calorie diet—less than 500 calories a day—that they would be put on before and after the surgery, but without the procedure itself. After a few months, when they gained weight, the same patients were actually operated on and repeated their diet, consistent with each day. This allowed the researchers to compare the results of caloric restriction with and without the surgical procedure – the same patients, the same diet, just with or without surgery. If there was some kind of metabolic benefit to the anatomical reorganization, the patients would have done better after the surgery, but, somehow, they did worse.
Calorie restriction alone resulted in similar improvements in blood sugar levels, pancreatic function, and insulin sensitivity, but several measures of diabetes control improved significantly without surgery. The surgery seemed to put them in a bad metabolic state.
Calorie restriction works by removing fat from the liver first. Type 2 diabetes is thought to be caused by fat building up in the liver and spilling into the pancreas. Everyone may have a “personal fat threshold” for safe excess fat storage. When that limit is exceeded, fat is deposited in the liver, where it can cause insulin resistance. The liver can then release some of the fat (a fat transporter molecule called VLDL), which then accumulates in the pancreas and kills the cells that produce insulin. By the time diabetes is diagnosed, half of the insulin-producing cells may have been destroyed, as seen below and at 3:36 in my video. Bariatric Surgery vs. Foods to Reverse Diabetes. Put people on a low-calorie diet, however, and this whole process can be reversed.
A large enough calorie deficit can cause a significant decrease in liver fat sufficient to stimulate insulin sensitivity in the liver within seven days. Continue, and a calorie deficit can reduce liver fat enough to help normalize pancreatic fat levels and function within just eight weeks. If you drop below your fat limit, you should be able to resume a normal caloric diet and maintain your diabetes, as shown below and at 4:05 in my life. video.
Bottom line: Type 2 diabetes is reversible with weight loss, if you catch it early.
Lose more than 30 kilograms (13.6 pounds), and about 90 percent of those who have had type 2 diabetes for less than four years can reach diabetes-free sugar levels (suggesting diabetes remission), while it can only be reversed in 50% of those who have lived with the disease for eight years or more. That’s just weight loss through diet, though. In people with diabetes, who lose more than two times their weight with bariatric surgery, the remission of diabetes may be about 75% of those who have had the disease for up to six years and only about 40% of those who have had diabetes for a long time, as shown below and at 4:41 in My video.
Losing weight without surgery may offer other benefits as well. Diabetics who lose weight through diet alone can significantly improve markers of systemic inflammation, such as tumor necrosis factor, while levels worsen when losing about the same amount of weight from gastric bypass.
What about diabetes complications? Another reason to avoid diabetes is to avoid its associated conditions, such as blindness or kidney failure that requires dialysis. Reversing diabetes with bariatric surgery can improve kidney function, but, surprisingly, it may not prevent the onset or progression of diabetic vision loss—perhaps because bariatric surgery affects quantity but not quality when it comes to food. This reminds me of a famous study published in New England Journal of Medicine that makes thousands of people with diabetes randomized to an intensive lifestyle program focused on weight loss. At ten years, the study was stopped early because the participants were no longer alive or had a few heart attacks. This is because they live on the same heart-stopping diet but in smaller portions.
Doctor’s Note
This is the third blog in a four-part series about bariatric surgery. If you missed the first two, check it out Mortality Rate of Bariatric Surgery for Weight Loss again Complications of Weight Loss Surgery.
My book How not to eat focuses only on sustainable weight loss. Check it out at your local library, or pick it up wherever you get your books. (All proceeds from my books are donated to charities.)
