Following a low-carbohydrate, high-fat diet improved measures of nonalcoholic fatty liver disease (NAFLD) and blood glucose control in people with type 2 diabetes, according to a new study presented at the 2022 International Liver Congress in London, England, and described in an article at Healio.
NAFLD is a widespread problem in people with type 2 diabetes that often goes unrecognized. This form of liver disease is linked to a number of health risks, including a higher risk of death at more advanced stages. NAFLD is also linked to severe hypoglycemia (low blood glucose) in people with type 2, and there is evidence that detecting and treating undiagnosed liver disease could lead to improvements in cardiovascular health. You may be able to reduce your risk for NAFLD by following certain dietary patterns, and for people with type 2 diabetes and obesity, bariatric surgery can help improve the measured of established liver disease.
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For the latest study, researchers at Odense University Hospital in Denmark recruited 185 adult participants with type 2 diabetes and NAFLD. Participants were randomly assigned to follow one of two diets for six months — either a low-carb, high-fat diet, or a “classic diabetes diet” that was high-carb and low-fat. There were no portion or calorie restrictions for either diet — participants were told to eat until they felt full.
The low-carb, high-fat diet was high in healthy fats like avocados, olive oil, nuts, and seeds, but also contained some high-fat dairy products like cheese and cream. The high-carb, low-fat diet was high in whole grains and other unrefined sources of carbohydrate like oats, potatoes, and starchy vegetables.
Participants underwent liver biopsy — to look at liver fat levels — and had their A1C level (a measure of long-term blood glucose control) measured both at the beginning of the study and after six months of following their assigned diet. During those six months, all participants had ongoing consultations with a dietitian and logged their food intake on an online food diary — so the researchers could see, in a sense, how closely participants followed their assigned diets.
Low-carb, high-fat diet linked to liver benefits
The main outcome the researchers were interested in — for participants in either diet group — was whether they experienced at least 2 points in improvement on what’s known as the NAFLD Activity Score, which takes different aspects of liver changes or damage into account. When it came to this specific outcome, the researchers found no significant difference between participants in the two diet groups. But more participants in the low-carb, high-fat group experienced at least 1 point in improvement on the NAFLD Activity Score — 70%, compared with 49% of those in the high carb, low-fat group.
But maybe even more importantly, the low-carb, high-fat diet appeared to be much more effective at halting the progression of NAFLD. Only 1% of participants in the low-carb, high-fat group experienced a worsening of their NAFLD Activity Score, compared with 23% of those in the high-carb, low-fat group. Participants in the low-carb, high-fat group also tended to have a lower A1C level, and they lost significantly more weight over the study period — an average of 5.7 kilograms (12.6 pounds), compared with 1.8 kilograms (4.0 pounds) in the high-carb, low-fat group. For members of the low-carb, high-fat group, this meant losing an average of 5.8% of their body weight.
The researchers noted that this study shows the promise of following a low-carb, high-fat diet for people with type 2 and NAFLD, especially because it didn’t involve any portion or calorie restrictions. While many different kinds of diets have been shown to be beneficial over a few months, the researchers were optimism that the kind of low-carb, high-fat diet used in their study could be sustained by many people over a longer period of time — although more research is needed to confirm that people can stick to this diet, and that its benefits last, beyond six months.
Want to learn more about protecting your liver? Read “Diabetes and NAFLD” and “Preventing Fatty Liver (NAFLD).”