Would this be the study in question? It also contains various references within it and apparently fasting as a weight loss method for the massively obese was very popular during that time(1970s-ish) but they abandoned it in favour of VLCD(very low calorie diets) and low carb because of the supposed 'risks' and unpredictability with different people's bodies in response to these extended fasts(even when controlling for all possible factors).