OFF to the gym with your other half? It may not do your waistline any good.
Women are likely to lose weight of a morning, men in the evening, a US study says.
And it is far from the only surprising gender difference regarding lifestyle choices.
From keep-fit and kip to sex and diet, we reveal why men and women are like shock, sorry, chalk and cheese.
Females’ mental health may brighten up if they eat less refined carbohydrates such as white pasta.
A US study found those who ate big amounts were a third more depression-prone.
Cheese, though, can help them avoid osteoporosis, as they have lower bone density than men.
Blokes, meanwhile, can eat more dark chocolate. A study at Aberdeen University found it boosts blood quality in both sexes but more in men.
Also working wonders for fellas is zinc-rich shellfish, making for healthy sperm and boosting immunity.
Men may argue with this one, but a team at Loughborough University reckon a woman’s brain works harder, by multi-tasking, so they need 20 minutes’ extra kip.
Sleep expert Jim Horne says: “Women do lots at once and are flexible, so they use more of their brain. Because of that, their sleep need is greater.”
As for fellas, they sleep better when sharing a bed with a partner, while women are often disturbed, at least according to a report in the journal Behavioral Sleep Medicine. Misters are also more likely than misses to be night owls.
Around 40 per cent of ladies have regretted jumping into bed on a first date, compared to just 27 per cent of the opposite sex.
In fact, more than a third of bokes claim to have found love after a first date ends in the sack.
But different sexual positions can mean varying calorie burns for him and her. She works off most while squatting over her lover, feet planted on the floor.
For him, it is best as she lies back, legs raised and behind her head.
Women should work out early in the day if they want to banish belly fat and lower blood pressure, a US study claims.
Research has also shown moderate to vigorous keep fit can mean a 30 to 40 per cent lower risk of breast cancer. When it comes to fueling up for a workout, a pre-gym meal is OK for her but not so great for him.
Dr Adam Collins, at the University of Surrey, found that women burn up to 22 per cent more fat because their bodies are programmed to protect carbohydrates and instead burn fat. Men tend to run down carbs.
Married men are often happier and healthier — but the same is sadly not true for their wives.
Paul Dolan, a professor of behavioral science at the London School of Economics, advises that unmarried, childish women are more likely to live longer.
On the other hand, chaps who have tied the knot can see their careers improve — and have a better stab at landing in that top one per cent of earners.
They will likely live longer, too, and be less prone to high blood pressure and avoid obesity.
Professor Dolan adds that married men tend to “calm down”, taking fewer risks and earning more money.