An ominous warning by one of India's leading nutritionists, that all but 3 million of the 23 million children born in the country this year will be physically and mentally impaired by malnutrition, has rekindled debate in the scientific community over food distribution and government anti-poverty programs.

Dr. Coluther Gopalan, director of the Nutrition Foundation of India, said that deterioration of the physical and mental capacity of a vast segment of India's 700 million population is undermining human resources and threatening future generations.

Relying in part on data from the National Nutrition Monitoring Bureau, Gopalan said in a paper presented at a population conference here, and in a subsequent interview, that diet deficiency in rural India has created a vast pool of physically and mentally stunted adults who choose mates of similar characteristics and beget a new generation of malnourished children.

The result, he said, is a "frightening" growth of "substandard survivors who serve to perpetuate the undernutrition scenario over successive generations."

The symptoms of the problem among India's poor, Gopalan said, form a "broad twilight zone of morbidity, functional impairment of various kinds, apathy, lack of sense of well-being, poor physical stamina and low productivity."

Although correlations between malnutrition and productivity or mental capacity have been made here before, none has been presented by a leading health scientist in such a stark statistical light and with such ominous implications for the future.

Based on past statistical patterns and current census data, Gopalan said, 3 million of the 23 million children born in India in 1983 will die before they reach the first year, and another 1 million will die before they complete childhood. Of the remaining 19 million, nearly 9 million will become adults with physical and mental impairments and reduced productivity because of serious undernourishment and poor health, and yet another 7 million will suffer milder malnutrition and less striking physical and mental impairment.

As a result, if current trends continue, the full potential for physical and mental development will have been achieved by less than 15 per cent of the children born, Gopalan said.

"All of the discussion on population control has been on quantitative terms, as if controlling the alarming growth in numbers alone is adequate for a solution. But the qualitative factor is causing far greater damage and should cause even more concern," Gopalan said in an interview.

Some health experts, foremost among them Dr. P.V. Sukhatme of the Association for the Cultivation of Science, have challenged Gopalan's conclusions and maintain that his fears are alarmist.

Sukhatme argues that only children with weight-age deficits of more than 40 percent are truly undernourished, and that stunted growth among rural poor may represent an adaption to environment.

Dr. Lincoln Chen of the Ford Foundation here said that while growth retardation from numerous causes is an obvious phenomenon in rural India, there is a dearth of statistical evidence with which to link it conclusively with undernourishment. He nevertheless ends up not far from Gopalan in his view of needed governmental programs.

"Outside of severe cases, I don't think there is a functional relationship. This is a biology topic with a lot of sociology in it. A social and economic process goes on at the same time, and the result may be a mixture of a lot of factors," Chen said in an interview.

Referring to the proponents of the adaptive-process theory, or the "small is healthy" school, Chen said, "What we don't know is the cost of the adaptive process. We know malnourished kids have a higher risk of dying, and everybody knows that in severe categories there are growth problems, but the question of whether there is a functional significance to mental and physical impairment among survivors is unclear."

Gopalan stressed that he was mindful of intensive efforts being made by the government--India probably has more direct feeding programs than any country but China. He called for a redistribution of food resources and new strategies for attacking glaring socio-economic disparities between urban Indians and the rural population, which comprises 85 percent of the total.

Protein calorie malnutrition is not India's only nutrition problem, although it probably is the most important, said Gopalan, who is former head of the Indian Council of Medical Research.

Iron deficiency anemia, which according to the National Institute of Nutrition affects 63 percent of children under age 3, has been shown to alter brain biochemistry and could alter behavioral patterns of entire segments of the Indian population, Gopalan said.

Moreover, goiter, or thyroid inflammation caused by iodine deficiency, affects 40 million Indians despite a 20-year national program of distributing iodized salt, he said. Although goiter can lead to severe retardation in extreme cases, studies by the All-India Institute of Medical Sciences show that the more common effect is slightly impaired development of children of goiterous mothers.

Preoccupation with population control, he said, provides a convenient alibi for leaders who are unwilling or unable to reorder national economic policy away from long-range self-sufficiency toward meeting critical immediate needs.

"You can't write off the present generation in planning for the future. Things are being done, but the attitude is to make short-term sacrifices for long-term economic gains," Gopalan said. For example, he said, sugar cane, whose export produces coveted foreign exchange, displaces food grains that could help alleviate malnutrition.

To redress the imbalance, Gopalan called for a minimum wage for agricultural laborers of 10 rupees (about $1) a day, or three times what some farm workers now earn, and implementation of food-for-work programs. He also recommended that 10 percent of the rural primary education budget be applied to an imaginative nutritional program, and that the family planning program be restructured to provide stipends, job training and nutritional guidance for unmarried girls instead of belated family planning assistance to women who have already produced children.

Other health scientists maintain that India's intensive rural development programs do not necessarily result in improved nutrition, especially among women.

Dr. Betty Cowan, of the Christian Medical College in Ludhiana, studied villages in the agriculturally prosperous Punjab, where only 11 percent of rural families live below the poverty line. She found that infant mortality has shown no decline and that the number of premature, underweight babies has increased.

Cowan concluded that while rural development benefited the landowning caste and increased work opportunities even for the poorest, women were burdened with more work and less time for infant feeding, resulting in severe malnutrition among 50 percent of the rural Punjabi girls and 20 percent of the boys below age 5.

Chen emphasized the link between malnutrition and diarrheal diseases, noting that nutrient wastage caused by parasitic diseases and infections leads to 1 million child deaths a year, and that an estimated 112 million children between six months and 3 years of age have two to 10 episodes a year of diarrheal diseases.

In addition to stepping up long-range water and sanitation improvement efforts, Chen urged immediate action, such as immunization, rehydration therapy and nutritional programs. He also proposed increasing the purchasing power of the poor through economic programs or attacking malnutrition through public distribution of food, and improving family nutrition management through education and job opportunities for women.