Skip to main content

1980s advice was over simplistic – but what type of diet best keeps our blood fat level in check? – Prof Victor Zammit

Victor Zammit, a Professor of Metabolic Biochemistry at Warwick Medical School, recently wrote a review for Biochemical Journal Vol 451, pp 1-12 in which he said:

Victor Zammit extract

Reacting to today’s news, Prof Zammit commented: “It has been obvious for some time that the advice given in the early nineteen eighties, namely, that saturated fat is the only harmful type of food when it comes to raised blood lipids and heart disease was over-simplistic. It also gave the impression that we could ingest as much carbohydrate as we liked, as this would not be dangerous.

“What was overlooked at the time is that the liver converts carbohydrate into fat very efficiently. Indeed, the type of carbohydrate that was substituted for fat in the diets of westernised countries was the worst of all, namely sucrose (sugar). Half of this is made of fructose which not only provides calories (and hence results in overweight and, eventually obesity) but also stimulates the liver to make fat and secrete it (packaged with cholesterol) into the blood where it causes heart disease. Therefore fructose has a ‘multiplier’ effect. Unfortunately, the need for the sugar industry to find a use for ‘corn syrup’ resulted in excessive consumption of sucrose (up to 20% of daily calories in some parts of the West) in fizzy drinks. And as long as it wasn’t fat, it was deemed to be fine, except that we now know that it isn’t because the liver is stimulated to convert it into fat anyway.

“However, this emphasises the fact that excessive fat in the blood (wrapped in ‘bad’ cholesterol) is known to precipitate cardiovascular disease, and that view has to be kept in focus. The issue is what type of diet best keeps our blood fat level in check. It has become evident that high carbohydrate diets are not beneficial, as they raise insulin and promote fat synthesis.

“Is saturated fat worse than unsaturated fat? The evidence is that it could be worse because obesity is not just a matter of excess weight, but is also a state of sub-clinical chronic inflammation, with inflammatory cells invading the expanded fat depots. These inflammatory cells secrete hormones that make other tissues (e.g. muscle and heart) resistant to insulin, and initiate vicious spirals that lead to type-2 diabetes and cardiovascular disease. Saturated fats favour inflammation (whereas monounsaturated ones antagonise this effect), so it is better to limit the amounts of saturated fat we eat.

“Just like fructose, it’s not just the large amount of calories that saturated fats carry, but the metabolic ‘multiplier’ effects that they exert which may be the most dangerous.”

Note to Editors:

Issued by Lee Page, Communications Manager, Press and Policy Office, The University of Warwick. Tel: +44 (0)2476 574 255, Mob: +44 (0)7920 531 221. Email:



Lee Page, Communications Manager

+44 (0)2476 574 255

+44 (0)7920 531 221