There is a general assumption every January that the whole world - as you and I and Ed Meese know it - has been gorging on rich food since Thanksgiving Day. Never does a new diet or exercise plan hit a softer market, in every sense of the word ''soft.''
With our guilt and New Year's resolutions working for them, the magazine editors of America spread promises over their January covers. Here is a sampling: ''How to Solve Your Body Problem''; ''Diet and Exercise Blitz''; ''Total Body Makeover''; ''Lose 35 pounds on Dolly's Diet'' - and if you happen to be one of the well-fed doubters, just look at the adjoining picture of the newly pert Parton .
Has anybody noticed how thin, how extra-relentless Richard Simmons looms in January? Peering into our downcast eyes, he and his fellow health bullies of TV seem to take special post-holiday delight in reminding us, in the tone of Old Testament prophets, how we've desecrated the temples that allegedly are our bodies.
All well and good, we suppose, as we thoughtfully polish off the last remnant of plum pudding. But - not to get carried away by the metaphor - it is curious how indignant people become about the ''junk'' food, the ''poison,'' their stomachs ingest while paying next to no attention to the ''junk'' food, the ''poison,'' ingested by their minds and hearts.
Where, we ask, are the moral equivalents to the tyrants of 50 pushups or the inventors of the all-celery diet? Where are the woe-sayers who will warn us against rotting our intelligence by wolfing down harmful quantities of ''Three's Company'' and ''General Hospital'' and ''Dallas''? Or perhaps you have pay-TV? Then you can turn off all that other junk and watch ''Creepshow,'' ''The Sex Machine,'' and ''An American Werewolf in London'' - to make a casual selection from a January schedule. Need we mention the latest franchise of malnutrition, music-video?
But let's not make it that easy for ourselves. If we're arguing - and we are - that Americans are subsisting on a low-nutrition diet of junk culture that makes French fries and candy bars look like a Spartan health program, we ought not to carry the day by taking cheap shots at just television and rock music.
Still, television and rock music do constitute the most popular cultural fare of the largest number of Americans. Then the menu tends to run from there to a la carte headlines about Liz and the Princess of Wales and Johnny Carson's alimony - to take a quick January survey - not forgetting your daily special from the astrology charts.to here If we were to send a reverse time capsule to Charles Dickens, Honore de Balzac, and Feodor Dostoevsky in order that those novelists, so in touch with the 19th century, might taste firsthand the late-20 th century, something like this unheavenly hash might, alas, represent us all too accurately.
All right, you say, but let's get to print and not simply the print of gossip sheets and Captain America comics. Let's check our standards against an honored traditional form that still persists: the book.
We take you now to a symposium of paperback publishers. Edwin McDowell of the New York Times raises the question: ''What does it say about the American public that so-called tasteless and gross joke books - books that contain explicit sexual references and racial and ethnic slurs - have become such huge best sellers?''
The paperback publishers respond with answers predicated on ''20 years of declining readership'' - a ''mass market'' today of maybe 5 million Americans, or about 2 percent. Voices of resigned realism describe their predicament: ''We competed in the late '70s and early '80s with video games, our readers have gone to home computers, we were blasted by television.''
One voice blunter than the rest sums up: ''I can't -ignore the fact that everything has moved down in quality. If I ignore that, then I begin to ignore what my job is. If shoddy workmanship, shoddy clothing, if the impersonalization of life is what it is, then I've got to get in tune with that.''
What an honest, what a ghastly, acceptance of things as they are supposed to be!
Of course this is not the whole story. Scholarly books and poetry and serious novels still get published, just as the complete piano works of Beethoven get played on FM radio. But meanwhile, every time we snap on our TV set or our car radio or pass a newsstand and - yes - open a book, we stand a pretty good chance of being force-fed junk.
''Our job is to survive,'' the paperback publishers said. But our job is to survive too - we, the consumers.
Too often something in us starves as we survive, concentrating on counting calories and performing calisthenics to a disco beat - atoning for our pre-New Year binges by our post-New Year crash courses in reform.
In the ways that count, we are not exercised, we are not fed.
Some day, with all the manic force he likes to muster, Richard Simmons should warn us that history won't much care how flat our stomachs are if that becomes our only ideal of fitness.