Losing weight may be especially difficult for people with fatty liver
disease due to differences in their metabolism. But nonetheless, some can
succeed and doing so improves liver health, according to studies presented at the
AASLD Liver Meeting last week in Boston.
Non-alcoholic fatty liver disease
(NAFLD) and its more severe form, non-alcoholic steatohepatitis (NASH), are responsible
for a growing proportion of advanced liver disease as obesity rates rise in the
global population. The build-up of fat in the
liver triggers cell death and inflammation, which over time can lead to
fibrosis, cirrhosis, liver cancer and the need for a liver transplant.
Linked to diabetes and insulin resistance, NAFLD/NASH
is increasingly recognised as a manifestation of the metabolic syndrome. There
are no effective medical therapies for the condition, and management relies on
lifestyle changes such as weight loss and exercise. A loss of 5% of body weight
or more has been shown to improve steatosis (liver fat accumulation).
- decompensated cirrhosis
The later stage of
cirrhosis, during which the liver cannot perform some vital functions and
complications occur. See also ‘cirrhosis’ and ‘compensated cirrhosis’.
Abnormal fat deposits in the liver.
"Globally, obesity and
NAFLD are an increasing cause of significant morbidity and mortality, with few
effective weight loss strategies available," presenting researcher Dr Ann
Farrell of St Vincent’s Hospital in Melbourne, Australia, said in an AASLD
press release. "As our understanding of the physiology of
obesity and weight homeostasis evolves, so too does our approach to the management
of weight loss."
Farrell and colleagues conducted a retrospective cohort study of obese individuals attending an
outpatient weight management clinic at St Vincent’s Hospital between July 2015
and February 2019.
Among the 211 evaluable people in the cohort, 113 were diagnosed with
NAFLD, defined as a fatty liver index (FLI) score of 60 or higher. The index is
based on body mass index (BMI), waist circumference and gamma-glutamyl
transferase (GGT) and triglyceride levels. People with heavy alcohol
consumption or other causes of liver disease were excluded.
age was 48 years. Participants with NAFLD were more likely than those without
NAFLD to be men (42% versus 22%) and to have type 2 diabetes (43% versus 27%).
Those with NAFLD had a higher weight, BMI and waist circumference, higher
levels of GGT and ALT liver enzymes and blood glucose as measured by HbAc1, and
greater liver stiffness, an indicator of fibrosis. People with NAFLD were less
active (18% vs 34 reported exercise), were more likely to have been obese as
children (52% vs 33%) and were more likely to have a family history of obesity
(88% vs 74%).
Participants were put on a ketogenic very low energy diet (VLED) that contained
800 calories per day for 12 weeks or until at least 5% weight loss was
achieved. The diet consisted largely of meal-replacement drinks, though they
were allowed one small meal each day to improve acceptability and adherence.
The very low carbohydrate diet is intended to induce ketosis – a state in which
the body gets most of its energy from fat rather than glucose – which has been
found to increase satiety and reduce hunger.
Prior studies have shown that people with type 2 diabetes lose less
weight on such a diet, and Farrell's group aimed to determine if this was the
case for people with NAFLD as well.
After three months on the
diet, 49% of people with NAFLD and 67% of those without NAFLD had managed to achieve
at least a 5% weight loss, a significant difference. However, by six months,
the rates had risen to 61% and 75%, respectively, and the difference was no
People with NAFLD lost less
weight than those without. At three months, the overall percentage loss of
total body weight was 4.9% in the NAFLD group and 7.6% in the non-NAFLD group.
At six months, the respective percentages were 9.0% and 11.3%. However, neither
difference was statistically significant.
After adjusting for other
factors, an FLI of 60 or higher – that is, a NAFLD diagnosis – was the only
predictor of not achieving at least a 5% weight loss.
"We found that a
smaller proportion of patients with NAFLD were able to achieve the target 5%
loss of total body weight at three months compared to those with a
non-diagnostic fatty liver index," Farrell said. "In our further
analysis, this difference was no longer evident when the cohort was followed to
six months. This suggests that while obese patients with NAFLD can still achieve
significant weight loss on a very-low-calorie diet, they may be slower to reach
"Overall, the weight
loss achieved through this outpatient-based diet program was significant,"
she added. "This is a strategy that should be considered in the management
of obese patients with NAFLD moving forward."