Eating used to be so simple. If you liked it and could afford it, down the hatch it went. Yum-yum, end of story.

But the days of carefree consumption of food, alas, are a thing of the past, especially for meat lovers.

Scientists have found a new contributor to male infertility, a protein that is supposed to coat sperm to help them swim to an egg, unless that coating goes missing.

About 20 percent of men may harbor gene mutations that leave their sperm coat-free and thus lower their fertility, an international research team reported.

A ban on sales of loose cigarettes and tobacco advertising went into effect Thursday in Colombia, the health ministry said.

The clampdown is part of an anti-tobacco law approved by Congress in June 2009, following a ban on smoking in enclosed public places in May 2008.

An inherited form of Alzheimer's disease is likely detectable up to 20 years before loss of memory and impaired thinking appear, according to a study released Wednesday.

Measurable changes in brain chemistry show up years before these signature symptoms of the degenerative brain disease set in, researchers reported at the Alzheimer's Association International Conference in Paris.

Male circumcision, an operation being promoted in Africa to help prevent HIV infection, boosts men's sexual pleasure, according to a study presented at the conference on AIDS medicine winding up here on Wednesday.

The probe is one of a panoply into the medical and psychological impacts of the fast-growing circumcision campaign.

Hong Kong researchers have found that men are more likely to develop liver cancer due to a type of gene which is linked to male sex hormones.

Researchers at the Chinese University of Hong Kong said a study conducted since 2008 found more than 70 percent of patients with liver cancer produced high levels of a gene called cell cycle-related kinase (CCRK).

Nearly one in five dishes served at U.S. restaurants has at least 100 more calories than advertised, a difference that could pack on up to 15 kilograms (22 pounds) per year, said a study on Tuesday.

While most of the 269 foods measured at random in the three-state survey were close to the calorie count listed on the menus, some varied wildly, such as one order of chips and salsa totaling 1,000 more calories than expected.

This week's heat wave may be uncomfortable, but you're healthy, active and feel just fine. So what if you're over 65? Think again. Feeling good doesn't mean you're safe.

There are changes in an older person that raise the risk for heat stroke and other problems. An older body contains far less water than a younger one. Older brains can't sense temperature changes as well, and they don't recognize thirst as easily.

A top Las Vegas casino resort has issued a health warning to past guests after six people came down with Legionnaire's disease, health authorities said Monday.

Citing "an abundance of caution," the Aria Resort & Casino has written to people who stayed there between June 21 and July 4 when tests showed elevated levels of Legionella bacteria in some of its guest rooms.

Binge-drinking can have a long-lasting negative effect on the brains of teenaged girls, hitting them harder than it does young boys, a study released Friday shows.

Researchers from the University of California, San Diego (UCSD) and Stanford University found that girls who binge-drink -- defined as having four or more drinks for women and five or more for men -- showed less activity in several brain regions than teetotal teenagers, both girl and boy, the study said.