For decades we've been told that saturated fats are bad for us and eating too much red meat, milk, cream and eggs should be avoided.
NHS guidelines state that eating large amounts of saturated fat can increase the cholesterol in our blood, and high levels of cholesterol can increase your risk of heart attack, stroke or narrowed arteries.
Public health advice states that the average man should eat no more than 30g of saturated fat a day and the average woman should eat no more than 20g of saturated fat a day.
New research, however, claims that the current dietary guidelines with regard to fat might not be the right advice, causing a storm of protests from health bodies and dieticians.
Reporter Jonathan Maitland investigates the controversy and asks whether a high fat diet can ever be healthy for us?
The concept of how fat can affect our health and lifespan started with the pioneering work of American scientist, Dr Ancel Keys, who helped establish the link between dietary fats, cholesterol, and heart disease in the 1950s.
Some academics now argue that the dietary guidance on how much fat we should eat lacks the solid scientific trials to back it up.
Obesity researcher Zoe Harcombe believes that the original advice about drastically reducing fat in our diet is flawed because the original trials were only undertaken on unhealthy men with no women included.
New York investigative journalist and author of ‘The Big Fat Surprise’ Nina Teicholz subscribes to what Zoe Harcombe is saying and believes more, not less, dietary fat - including saturated fat - is what leads to better health, wellness, and fitness.
Official public health guidance still maintain that carbohydrates such as potatoes, cereals, pasta, rice and bread should make up around one third of the food people eat.
So, what about fat? The British Heart Foundation believe that Zoe Harcombe’s findings should not mean that guidance should be reversed.
So can you eat fat and be fit? Endurance runner Terry Conway runs up to 100 miles at a time on a healthy high fat diet.
Tonight put five volunteers, male and female, on a diet provided by Dr Arun Ghosh which was high in fats from non-processed foods. This meant eating lots of fat and cholesterol from natural foods such as avocados, full fat milk, eggs, oily fish, meat as well as lots of fruit and veg but easing off the carbohydrates.
The volunteers were on the diet for 7 days and overall everyone had a good experience of eating healthy fats from non-processed foods with and most had some cholesterol and weight reduction.
Dr Ghosh felt that we could not draw too much scientific conclusion from the results but he was interested to see how different people coped with the diet. He was encouraged that some lost weight and saw a slight drop in their cholesterol but the best result was that the diet caused none of the volunteers any harm.
The Food and Drink Federation strongly agree that dietary guidance and public health policy should be underpinned by robust and up-to-date science which informs consumer behaviour and industry action.
Endurance running event: