Just one month of eating fast food and walking less than 5000 steps in a day is all it takes to impair liver function. That’s what scientists found in a study published in Gut, a peer review journal for health professionals and researchers in gastroenterology and hepatology. Just for reference, some doctors recommend that normal, healthy individuals should walk about 10,000 steps (or about one hour) per day.
In the study, there were 18 healthy people (12 men, 6 women) and a matched control group. The subjects in the intervention group ate at least two meals at popular fast food restaurants each day and restricted their physical activity to not more than 5000 steps per day. Their mission was to increase their body weight by 5 – 15% by doubling their normal daily caloric intake and adopting a sedentary lifestyle for four weeks.
In order to monitor liver function, blood samples were taken at the beginning of the study and at regular intervals thereafter. One way to identify liver damage is to measure alanine aminotransferase (ALT), an enzyme in the liver. After only a single week on the fast food diet, ALT levels in the intervention group began to climb.
By the end of the four weeks, seventeen of the eighteen subjects had met their goal of increasing their body weight by 5 – 15%, with 5 of the eighteen subjects reaching the 15% mark. Thirteen of the study participants developed pathological ALT, which was evident in most subjects after the first week. Those in the control group did not experience any such increases.
It doesn’t take a rocket scientist to see that a sedentary life of fast food gluttony will rapidly lead to ill health. While one may wonder why anyone would agree to participate in such an experiment, the good news is that it may be possible to reverse liver damage caused by such a lifestyle, according to a Saint Louis University press release. The way to undo the damage to the liver and other vital organs is to adopt a healthy lifestyle.
Brent Tetri, M.D., professor of internal medicine at the Saint Louis University Liver Center and preeminent expert on non-alcoholic fatty liver disease, conducted a similar experiment using mice. “There’s strong evidence now that a fast-food type of diet — high in fat and sugar, the kind of diet many Americans subsist on — can cause significant damage to your liver and have extremely serious consequences for your health,” he explains. “The good news,” he continues, “is that most people can undo this damage if they change their diet and they keep physically active. If they don’t, however, they are asking for trouble.”
In the study conducted by Dr. Tetri, mice were given a diet that was 40% fat and loaded with high-fructose corn syrup, a sweetener commonly found in sodas, juices, and bottled sauces and dressings. The mice were also kept sedentary, emulating the lifestyle of many Americans. After four weeks, the mice displayed an increase in liver enzymes and the onset of glucose intolerance, known to be a marker for type II diabetes.
Dr. Tetri points out that while not all fast food necessarily causes liver damage, the problem is a diet containing too many calories with too much fat and sugar (typical in fast food meals consisting of burgers, fries and sodas). Tetri adds, “The fact we’re starting to see kids with liver disease should really be a wake-up call for anyone eating a diet high in fat and sugar and who’s not physically active.” He offers some encouragement to fast food junkies: “Even for those people with the worst kind of diets, it’s not too late to start exercising and eating right.”