He continued his education at Downing College, gaining an MA in natural sciences and PhD in immunology in January 1955.

He continued this study while at the Department of Pathology and was secretary for the first International Symposium On Atherosclerosis held in Athens in 1966 and was an editor of the proceedings.

[4] In 1968, Howard published results of a clinical trial on the use of a high-protein "Cambridge Formula Loaf" for treatment of obesity.

[8] Howard and George A. Bray (from the University of California) organised the first International Congress on Obesity (ICO) which was held at the Royal College of Physicians in London in October 1974.

While in the Department of Medicine at Cambridge University, Howard's team ran a "lipid clinic" at Addenbrookes Hospital between 1973 and 1980.

He collaborated with Ian MacLean Baird, then a consultant at West Middlesex Hospital, to devise a low-calorie diet formula for morbidly obese patients.

The COAG Laboratory ran until 2000 carrying out research into aspects of nutrition and health, especially the prevention of coronary heart disease.