Here is a very provocative paper which emphasizes the need for less use of ATB in cattle ans humans.
So ATB is a growth factor for farm animals I mean chicken, veals etc.
What about humans?
"After raising chicks on Aureomycin-laced food and on ordinary mash, he found that the antibiotics did boost the chicks’ growth; some of them grew to weigh twice (the bold types are mine) as much as the ones in the control group."
" In fact, a number of scientists believed that antibiotics could stimulate growth in children. "
"In 1954, Alexander Fleming — the Scottish biologist who discovered penicillin — visited the University of Minnesota. His American hosts proudly informed him that by feeding antibiotics to hogs, farmers had already saved millions of dollars in slop. But Fleming seemed disturbed by the thought of applying that logic to humans. “I can’t predict that feeding penicillin to babies will do society much good,” he said. “Making people larger might do more harm than good.”"
"Mr. Jukes summarized Dr. Carter’s research in a monograph on nutrition and antibiotics: “Carter carried out a prolonged investigation of a study of the effects of administering 75 mg of chlortetracycline” — the chemical name for Aureomycin — “twice daily to mentally defective children for periods of up to three years at the Florida Farm Colony. The children were mentally deficient spastic cases and were almost entirely helpless,” he wrote. “The average yearly gain in weight for the supplemented group was 6.5 lb while the control group averaged 1.9 lb in yearly weight gain.”
Researchers also tried this out in a study of Navy recruits. “Nutritional effects of antibiotics have been noted for some time” in farm animals, the authors of the 1954 study wrote. But “to date there have been few studies of the nutritional effects in humans, and what little evidence is available is largely concerned with young children. The present report seems of interest, therefore, because of the results obtained in a controlled observation of several hundred young American males.” The Navy men who took a dose of antibiotics every morning for seven weeks gained more weight, on average, than the control group."
" What happens when chocolate doughnuts mix with penicillin?The results of the study were dramatic, particularly in female mice: They gained about twice as much body fat as the control-group mice who ate the same food. “For the female mice, the antibiotic exposure was the switch that converted more of those extra calories in the diet to fat, while the males grew more in terms of both muscle and fat,” Dr. Blaser writes. “The observations are consistent with the idea that the modern high-calorie diet alone is insufficient to explain the obesity epidemic and that antibiotics could be contributing.”"
Cesarean section: a way to obesity?
"Children born by C-section are more likely to be obese in later life."