FOOD PRICES are very likely to keep rising briskly throughout the year and, sad to say, there's not much that anyone can do about it. Not the brave new Carter administration, not the farmers, not the consumers with strikes and boycotts. Over the past generation, to be blunt, Americans have got a bit spoiled regarding food prices. Most of us consider it a law of nature that the price of food should be low and stable - and that, when prices rise unecpectedly, it's some villain's fault. But now prices are going up for reasons that lie well beyond any governments command.

The freeze in Florida will show up in the price of orange juice, fruit and vegetables. But much more important and more lasting, a great drought now threatens next summer's crops throughout the West. The snow pack in Colorado is one-third its normal depth, and that snow feeds a river system on which Southwestern agriculture is crucially dependent for irrigation. In California's Sierras, the precipitation over the past half-year has been one-sixth the normal rate.

Some delayed effects of previous trouble are also about to catch up with us. The full effects of past years' jumps in grain prices have not yet been fully passed through to the retail price of beef. With higher feed costs, a lot of stock raisers have been losing money on their steers and have been sending them to market in large numbers to get rid of them. The herds are now being shrunk to profitable numbers. When this process is complete, the amounts of beef coming to the consumer will drop sharply. You'll know what it's happened when the price of steak and hamburger starts to rise.

It doesn't mean that Americans are going to starve to death. People have been known to survive, and sometimes even to prosper, without beef - just as it's also possible to live without coffee. But it's going to mean another shift in our national dietary habits. By the year's end most Americans are probably going to be eating a good deal less beef, and more pork and chicken.

It's an unpleasant jolt to an established American state of mind. Until the mid-1970s, most of us thought that technology had stabilized food production for all time. There was good reason to think it. For a quarter of a century, from 1948 to 1973, prices at the grocery store rose less rapidly than consumer prices in general. To put it more sharply, food prices rose one-fifth as fast as incomes. The country got used to spending a steadily smaller proportion of its earnings on a steadily richer diet.

The things suddenly swung around with a speed and force that no one had foreseen. Foreign sales rose dramatically, while the American population was growing. Dependence on fertilizers and irrigation was growing with it. Since 1973, food prices have been rising markedly faster than the consumer price average. Food prices have been rising, in fact; half again as fast as incomes. The 25-year pattern has reversed itself, and food costs are now taking a growing share of families' budget.

The federal government has a responsibility to build shock absorbers into the system, to soften the impacts of inpredictable shifts in world trade or the weather. It's hardly necessary to argue once again the case for rebuilding grain reserves. But no government can guarantee for the late 1970s the kind of stability that this country enjoyed in grocery prices through the 1950s and 1960s. One basic reason is that weather patterns seem to be changing. The weather, unfortunately, follows a law that is not subject to amendment by Congress.