From Christina Tsuei and Shirley S. Wang:
You have seconds on turkey and thirds on stuffing. The top button is unfastened to make room for the pumpkin pie. It is time to step away from the table.
This post-meal recovery period is being studied by scientists who are increasingly finding that what happens in the body after eating a big meal doesn’t just bring on sleepiness, commonly known as food coma. It can also increase the risk of later health problems.
Everybody absorbs fats, sugars and other nutrients differently. These variations can provide clues about a person’s risk for common medical conditions, including heart disease, stroke and diabetes, research shows. Even in healthy people, cells that line the blood vessels temporarily function less efficiently after a person eats a high-fat meal.
Researchers also are studying strategies for reducing risks in the period immediately after a meal, known as the postprandial phase. While going for a walk after eating might help digestion, for example, recent studies suggest that exercising 12 or more hours before the meal can prevent one of the most damaging effects—a post-meal spike in a type of fat called triglycerides.
One of the biggest tasks for the body after eating is to deal with fats in the blood. Cholesterol, particularly LDL, or “bad” cholesterol, infiltrates the walls of the arteries and forms plaques, which can block blood flow or eventually rupture, leading to heart attack and stroke. The condition is known as atherosclerosis.
Triglycerides, which typically peak after a big meal, are present in food and are also converted by the body from other nutrients, like carbohydrates. Triglycerides are particularly problematic because they are so good at penetrating the arterial wall, says Borge Nordestgaard, chief physician in clinical biochemistry at Denmark’s Copenhagen University Hospital….
Spurred in part by the research, Denmark has shifted its clinical practice. Lipid tests are now typically given to patients who aren’t fasting to screen for health risks. If any lipids are elevated, patients then are also screened in a fasting state, Dr. Nordestgaard says.
Light exercise like a slow walk, done continuously for 30 minutes or more, appears to reduce the peak in triglycerides that occurs after eating a meal some 12 to 16 hours later, according to research led by Peter Grandjean, director for the Center for Healthy Living at Baylor University in Waco, Texas.
It’s unclear exactly why there is a delay, but exercise induces a number of cellular responses that require different amounts of time before taking effect, Dr. Grandjean says.