Without straining or tiring yourself, you can walk off 12 pounds a year.

Diet quacks announce triumphantly that it takes 35 miles of hiking to lose 1 pound of fat. Who has the time or energy to stroll 35 miles, say the faddists. No one, of course, except perhaps a boxer in training, and chances are that he's in better trim than you or I. At any rate we hope so, for his survival.

It's true that we don't take daily 35-mile jaunts. However if we walk 1.2 miles more per day than we do now, our strolls will add up to 35 miles each month. This amounts to a pound of weight each month, or 12 pounds a year. Chances are that during your ascendancy to obesity you did not gain this much in a single year.

"Walk, do not ride", might very well become America's slogan in routing obesity. Every time you pace off a mile you burn up about half an ounce of food - and it does not matter very much how fast or slowly you walk. The athlete who blazes a mile in slightly less than four minutes grabs the headlines, but the businessman or housewife who ambles the distance in half an hour gains equal benefits without heart strain.

The time has come to stop debunking exercise. If we have to debunk anything, let us debunk the mechanization which has padded so many American housewives with unnecessary fat.

Altogether it is safe to say that the wonders of mechanization make a difference of about 1000 calories a day to you as a modern housewife. Seven thousand extra calories add up to 2 pounds a week. Now it is quite true that you do not gain 104 pounds a year. You eat less food than your mother did because you utilize less energy.

Besides, you could not gain as much as 100 pounds because each new weight gain requires more calories to maintain obesity. The heavier you are, the more you must eat to keep that unattractive fat, and even the most obese people have their limits of food consumption. However, most housewives have not reduced their intake of food in proportion to their reduction of activity around the house. It is reasonable to assume that in many cases weight gains of 10 to 15 pounds a year are attributable to the replacement of human energies by machines.

Exercise Can Help You

I am not pleading for a return to the "good old days" of endless washing, cleaning, and cooking. Your new leisure should be used to make your life richer and more interesting. The hours of freedom should broaden your personality but not your hips. They should provide healthful physical exercise as well as mental stimulation. An occasional eighteen holes of golf, for example, involves about 600 calories of walking, swinging, and despairing. There are added bonuses of muscle tone, and a healthy complexion painted by sun and wind is most attractive.

For the nongolfer, walking is the exercise supreme. Not so long ago the walk was a social grace. You and your husband, strolling arm in arm through city and country, can gain a new appreciation of your surroundings and of each other. In the process you become trimmer at the rate of 75 to 100 calories per mile.

Dancing is another form of enjoyable exercise usually discarded well before middle life. This is an especially delightful way to shed 170 calories an hour. It is likely that a renewal of the dancing which was so important before marriage will lead to a rebirth of grace, agility, and coordination. In any case you will gain more from an evening of fox trotting than an afternoon at a charm school - and the bill will be much less.

It is quite true that exercise without regard to eating habits may be of no consequence in losing weight. But the combination of moderate exercise with moderate dieting is irresistible. In fact it is imperative.

As little as 30 minutes of exercise per day will do wonders for your waistline.