Fast food + coffee = bad idea

[Posted: Mon 04/04/2011 by Deborah Condon www.irishhealth.com]

It is already known that eating a fatty fast food meal is not good for your health, however washing that meal down with a cup of coffee may be even worse, the results of a new study indicate.

Canadian researchers have discovered that not only does a healthy person's blood sugar levels spike after eating a high fat meal, this spike doubles after having both a fatty meal and a coffee.

In fact, blood sugar jumps to levels similar to those of people at risk for diabetes.

"The results tell us that saturated fat interferes with the body's ability to clear sugars from the blood and when combined with caffeinated coffee, the impact can be even worse," the team from the University of Guelph said.

This is the first study to examine the effects of saturated fat and caffeinated coffee on blood sugar levels using a novel fat cocktail which contains only lipids. This specially designed beverage allows researchers to accurately mimic what happens to the body when we ingest fat, such as when we consume a fast food meal.

For the study, healthy men drank about one gram of the fat beverage for every kilogram of body weight for their first meal. Six hours later, they were given a second meal consisting of a sugar drink.

Typically when we ingest sugar, the body produces insulin, which takes the sugar out of the blood and distributes it to our muscles, the researchers explained.

However, they found that the fatty meal affected the body's ability to clear the sugar out of the blood. The subjects' blood sugar levels were 32% higher than they were when the men had not ingested the fat cocktail.

The researchers also tested the impact of caffeinated coffee combined with the fatty meal. For this test, participants received the equivalent of two cups of caffeinated coffee five hours after ingesting the fat beverage. An hour later, they were given the sugar drink.

The results showed that blood sugar levels increased by 65% compared to what they were when participants had not ingested the fat and caffeinated coffee.

"This shows that the effects of a high fat meal can last for hours. What you eat for lunch can impact how your body responds to food later in the day," the researchers noted.

Besides testing the participant's blood sugar levels, the team also looked at gastrointestinal effects by measuring incretin hormones released by the gut after ingesting the fat. These hormones signal the pancreas to release insulin to help clear the blood of sugar.

The team discovered that these hormones' responses to carbohydrates are blunted after ingesting the fat beverage.

"Ultimately we have found that fat and caffeinated coffee are impairing the communication between the gut and the pancreas, which could be playing a role in why participants couldn't clear the sugar from their blood as easily," the researchers said.

They pointed out that these results are particularly important for people at risk of metabolic diseases and type 2 diabetes.

"We have known for many years that people with, or at risk of, type 2 diabetes should limit their caffeine intake. Drinking decaffeinated coffee instead of caffeinated is one way to improve one's glucose tolerance.

"Limiting the intake of saturated fatty acids found in red meat, processed foods and fast food meals is also beneficial. This study has shown that the effects of these foods can be severe and long lasting," they added.

Details of these findings are published in the Journal of Nutrition.