- Eating one unhealthy meal is enough to temporarily alter the body's metabolism
- Fitter adults should be able to recover from one such meal, researchers claim
- But regular big helpings of rich, fatty foods are likely to cause lasting damage
Eating a single cheeseburger and a portion of chips is enough to temporarily alter the body's metabolism, experts have found.
Consuming the saturated fat contained in just one unhealthy meal can trigger changes linked to fatty liver disease and diabetes, a study suggests.
While a fit body might be able to recover from one such meal, regular big helpings of rich, fatty food are likely to cause lasting damage, the scientists say.
Consuming the saturated fat contained in just one cheeseburger can trigger changes linked to
fatty liver disease, a study suggests
Experts at the German Diabetes Centre in Dusseldorf tested their theory on 14 healthy men aged 20 to 40.
Each volunteer was given either a glass of vanilla-flavoured palm oil or a glass of plain water.
The palm oil contained as much saturated fat as an eight-slice pepperoni pizza or 110g cheeseburger served with a large portion of french fries.
Tests showed that consuming the palm oil resulted in an immediate increase in fat accumulation and reduced sensitivity to insulin, the vital hormone that regulates blood sugar.
It also raised levels of triglycerides - a type of fat linked to heart disease - altered liver function and led to changes in gene activity associated with fatty liver disease.
Levels of glucagon, a hormone that stops blood sugar falling, were also raised.
Similar effects were seen in mice given the same palm oil treatment.
While a fit body might be able to recover from one such meal, regular big helpings of rich, fatty food
are likely to cause lasting damage - including diabetes
The researchers, led by Professor Michael Roden, wrote in the Journal of Clinical Investigation: 'The practical implication of this work is that the palm oil challenge used in this study most likely resembles the effects of ingestion of a meal rich in saturated fat, eg an eight-slice pepperoni pizza or a meal consisting of a 110g cheeseburger and a large portion of french fries.
'One such meal would probably be sufficient to induce transient insulin resistance and impair hepatic [liver] metabolism.'
The scientists added: 'We presume that lean, healthy individuals are able to compensate adequately for excessive intake of saturated fatty acids, however, sustained and repeated exposure to such nutrients will ultimately lead to chronic insulin resistance, and non-alcoholic fatty liver disease.'
Palm oil was found to reduce insulin sensitivity by 25 per cent in the whole body, 15 per cent in the liver and 34 per cent in fat tissue.
Triglyceride levels in the liver were increased by 35 per cent and the mechanism that generates glucose sugar from non-carbohydrate foods became 70 per cent more active.
