Nutritional scientists, along with the biochemists, are proving more conclusively every day that most of your ills have their beginnings in poor eating habits.

If you want to carry your years lightly toward a longer, happier life, rather than allow the years to drag you along through a miserable, ailing, premature old age, you must take time to analyze your current eating habits. Compare them, one by one, with the stay-young dietary habits that make for a stronger, younger-looking, more vigorous you.

The first thing you need to do if you want to stay healthy is make a planned diet part of your eating habits.

The kind and quantity of food you eat are largely a matter of habits formed in early childhood. This often explains why obesity runs in certain families, although the fatties may try to explain away their overweight by blaming it on an "inherited family trait." Usually the tendency toward obesity lies, instead, in a common family habit of indulging in large meals of rich, starchy foods. Similarly, the persons who "don't like" this, that or the other food are merely following some childhood eating habit.

From the age of thirty onward, if you value your health, good looks and ability to live a long and vigorous life, you must change your eating habits.

The high-energy carbohydrate foods that were tolerated during your earlier years now slow you down and build up deposits of fat in dangerous places. After the super-active childhood years, the exhausting teens and the procreative twenties, few of us are called upon to expend the same amount of energy for daily survival as did our more primitive ancestors. Yet many people go on eating a lumberjack's diet while doing work no more strenuous than sitting at a desk for a few hours a day, or performing a few modernized and mechanized household duties.

After the age of thirty, preferably, and most certainly after 40, you must begin taking stock of your eating habits.

This means more protein and vitamin-rich fruits and vegetables. And less - perhaps none at all - high-starch foods such as rich desserts, all-starch items like white rice and macaroni, fattening bonbons, highly sugared and carbonated soft drinks, or overindulgence in alcoholic beverages.

This menu-in-a-nutshell is your first and most important step toward the goal of a longer life and a younger-looking body. From now on you must accustom yourself to topping off a meal with fruits (or the permissible desserts) rather than with the rich pastries, cakes, candies and jellies you have formed a habit of expecting at the end of every meal. One of the best means of keeping your sweet tooth under control is by looking to honey, nature's own confection, and the only sweet food, besides fruits, that contains valuable food elements.

Bad food habits at any time, and especially during the years that subject men and women to the ordeal of their climacteric (change of life), may be the underlying cause of a physical and mental breakup that can devastate any remnants of youthfulness left to them.