Health & Fitness - Equal Bites?

(IsraelWire-7/7/00)  When choosing clothing, men and women 
frequently select unisex fashions. But when food is the 
commodity, men and women simply can't follow the same patterns. 
Gender influences eating habits, activity patterns and specific 
nutrient needs. You can learn how to fine-tune your "sex specific" 
diet to achieve peak performance.

Boys and girls begin to develop different nutritional needs just 
before puberty, and these patterns continue through old age. For 
starters, calorie requirements differ widely between men and women. 
Men can usually eat 50% more calories than most women. This single 
factor accounts for many of the nutritional problems that plague 
women. Whereas men usually need from 2,300-2,700 calories per day 
to maintain weight, women require only 1,600-2,400 calories.

In part, body composition accounts for these gender differences 
in energy needs. Starting at age 12-14, males gain proportionately 
more lean tissue and less fat than females. And because lean tissue 
utilizes more energy than fat tissue, males need to take in more 
calories.

When you add exercise to the energy balance equation, women also 
expend fewer calories for the same activity. A 77 kg man, for 
example, burns about 640 calories on an 8.2 km jog/run, while a 
59 kg woman expends about 460 calories for the same distance at 
the same pace. This difference is due not only to gender but 
also to body size: More energy is needed to move a larger body.

This inequity in calorie needs presents different problems for 
each sex. Some men particularly bad-training exercisers/sportsmen, 
find it hard to enough food. To maintain optimum weight, these 
sportsmen/exercisers must schedule extra meals and include 
certain high-calorie foods (nuts, dried fruit, cheese) to meet 
their energy needs. 

By contrast, many women, despite being regular exercisers, 
struggle to treat their nutrient requirements on the low-calorie 
diets they frequently follow to maintain ideal body weight. 
For example, a group of elite women runners who averaged 112 km. 
A week took in only 2,300 calories a day with 11% of the runners 
eating less than 1,500 calories a day.

By eating so little, many women develop vitamin and mineral 
deficiencies. This may explain why surveys have shown that less 
than 25% of women meet their requirements for iron, zinc, calcium, 
foliate and vitamin B6.

Compared to women, men also have greater protein, vitamin and 
mineral requirements, with the exception of iron and possibly 
calcium. This gap is primarily due to body size differences.

For instance, regardless of sex, the body needs 0.8 grams of 
protein per kilogram of body weight. Most men never have difficulty 
consuming enough protein because they consume more than enough 
calories to meet their needs.
But women, particularly endurance athletes, many have inadequate 
protein intake because of caloric restriction in the diet. 
n other words, while 12-15% of the total calories coming from 
protein is sufficient for men, active women need to consume 
15-20% of the total calories coming from protein to ensure 
adequate intake.

Certain minerals may also be of particular concern to male and 
female serious exercisers/sportspeople. In male athletes, both 
magnesium and zinc become depleted as a result of exercise. 
While research has not established that requirements for these 
minerals change with regular exercise, athletes/serious 
exercisers who have marginal mineral status may be compromising 
their performance if they don't get enough of these minerals. 

Another "risk mineral" for both male and female serious
exercisers/sportspeople is iron. Men who consume low-calorie 
diets and exercise hard may risk iron depletion and a decline 
in performance. Women,due to their greater iron needs and 
generally lower calorie intake, face a lifelong "iron crisis." 
A women should consume 18 milligrams of iron daily but the 
average diet supplies only 6 milligrams per 1,000 calories. 
That is why poor iron status is more common in women exercisers / 
athletes - especially distance runners - than in their male 
counterparts.

Despite this crisis, iron supplements are not necessarily the 
solution. Large amounts of iron can decrease zinc absorption 
and deplete the body's supply of zinc.

Gender difference also appears in the case of calcium. 
While men and women have equal requirements of this mineral 
(800mg/day), calcium is clearly a female issue. Women lose 
calcium from their skeletons at a faster rate than men do, 
particularly when estrogen levels are low - after menopause or 
when amenorrhea occurs. Such women may need as much as 1,500 
milligrams of calcium daily to help prevent osteoporosis.

Another crucial nutrient for women athletes/exercisers: 
riboflavin, a B vitamin involved in energy metabolism. 
Women who exercise regularly require one - and one half times 
the RDA recommendation for riboflavin. One recent study 
revealed that older women (50-67 years) who bicycled for 30 
minutes, six days a week, showed increased need for riboflavin.

Along with nutrient needs, male and female eating habits 
contrast as well. For instance, more women than men are 
dieting at any given time, hence women are restricting not only 
calories but vitamins and minerals, too. Also, a vegetarian 
diet may lead to poor iron status. Thus, vegetarian exercisers / 
runners seem to be at particular risk of nutritional trouble.

Men are not immune to poor eating patterns, which can lead to 
low nutrient intake. Sporadic meals and a greater use of 
nutritional supplements such as protein powder can contribute 
to a less than ideal diet. Also, men are generally not as 
nutritionally aware as women, which in turn can result in
poor food selection.

But fear not. Include foods high in nutrient density is 
essential nutrients to make your diet "sex specific" and bridge 
the gender gap. 

Men: To get more magnesium, iron and zinc, regularly include 
green leafy vegetables (spinach, bok choy), whole grains 
(wheat, oats), legumes (kidney or pinto beans, lentils), 
dried fruits, lean meats, chicken , fish etc.

If keeping your weight up is a problem, increase the number 
of meals each day and eat more calorie - and nutrient dense 
foods such as nuts and nut spreads, dried fruits and whole 
grain dishes made with cheese or cream sauces.

Women: To satisfy your needs for calcium, iron, zinc and 
riboflavin, eat low-fat or skim dairy products, green leafy 
vegetables, whole grains, legumes, dried fruits, tofu, lean 
meats, chicken, fish etc.

To keep nutrient intake high and calorie balance in check, 
choose nutrient-dense foods such as those mentioned above 
and limit sugary and fatty foods.   

Health/Fitness/Nutrition & Total Lifestyle Consultant
Fitness of Body & Mind
(02) 566-2921; (052) 865821
fax (02) 572-4573
Email dr_bruner@hotmail.com