Does High-Fat Fast Food Mean a Lower Risk of DCS?

Will downing a Big Mac or a bucket of extra-crispy KFC before a dive reduce your chances of getting bent?

Research suggests that both the uptake and elimination of nitrogen are increased by increased amounts of fat (lipids) in circulating blood. Also, a high-fat meal temporarily escalates heart output pressure. A short report recently published in the July issue of Aviation, Space, and Environmental Medicine investigated the hypothesis that since nitrogen is five times more soluble in fat than water, fatty blood circulating at increased pressure might speed the rate of nitrogen off-gassing.

A group of 10 young, healthy men were allowed nothing but water after midnight the day before the experiment, then they were randomly given a low-fat control meal and a high-fat experimental meal, at least a week apart. The latter meal contained three to five times the amount of fat consumed by Americans in an average meal, upping the triglyceride level in the blood by about 250 percent% over that for the low-fat meal.

Nitrogen washout, which was measured about three hours after each meal, did not differ significantly between the low-fat and high-fat meals. Cardiac output increases did not result in significantly increased blood flow in the calves.

The conclusion: It's very likely eating a greasy meal prior to a dive won't reduce your DCS risk, but it still may allow you to enjoy the taste of it multiple times over the course of a dive.

- - Doc Vikingo