Hi Team, 

“A processed food is a food item that has had a series of mechanical or chemical operations performed on it to change or preserve it.” (Sidney Fry, 2015). Its important to remember that processed foods aren’t just microwave meals and other ready meals. A processed food is any food that has been altered in some way during preparation. 

A non processed food is any type of food found in its natural state that has not been altered. 

Although people still struggle to understand the simplicity of energy balance. It is now more understood that creating a calorie deficit is the key to weight/fat loss, and creating an energy balance or an energy surplus is the key to maintaining or gaining weight.

When losing body fat is an individuals goal. Calories in vs calories out is the most important consideration.

However, it is widely thought that processed foods may affect have an affect on weight gain and appetite. A recent study was conducted to test how much ultra-processed foods impacted peoples appetite.

The Study: 

–  Twenty people gave up a month of their time to live in a laboratory (overtime I read a scientific paper I still ask myself, who are the people that put themselves forward for these studies?) 
– Subjects undertook two weeks of an ultra-processed or unprocessed diet before switching to the alternative diet 
– All meals were designed specifically to contain the same amount of macronutrients and energy density 
– The participants were allowed to eat as much or as little as they wanted and researchers closely monitored what passed their lips

The Results: 

– During their ultra-processed foods fortnight, the volunteers, on average, ate an extra 508 calories a day
– Changes in body weight were highly correlated to changes in calorie intake (obviously!)
– Body weight increased by 0.8kg during the ultra-processed diet period 
– Body weight decreased by 1.1kg during the unprocessed diet period

To Conclude: 

An ultra-processed diet resulted in a significantly higher calorie consumption on average of 508kcal and therefore an increase in body weight on average of 0.8kg. This data presents with the theory that limiting consumption of highly processed foods may be a sensible strategy for individuals wanting to lose weight as well as obesity prevention and treatment. 

Dr Hall, from the National Institute of Diabetes and Digestive and Kidney Diseases, told BBC News: “This is the first study to demonstrate that there is a causal relationship. Therefore, It’s suggestive that this may be playing a role in the larger population.

Dr Hall said previous studies have estimated the “obesity epidemic” in the US was caused by people eating an extra 250-300 calories a day, and although these are only studies it represents evidence to suggest that we are overeating and ultra-processed foods are certainly not helping the situation. So, why did the individuals on the ultra-processed diet consume on average 508 more calories a day? The study has made a few assumptions and did show that the levels of the hunger hormone Ghrelin went down on the unprocessed diet. Ghrelin being a hormone that increases your appetite, therefore this may suggest that a diet high in ultra-processed foods increases your appetite due to the affects on hormones in charge of appetite. More studies will be required to back up this theory though. 

Its important we take on this information and use it to our advantage. So, although we know that energy balance is the key to weight management we now know that its more difficult to control energy balance when consuming a diet high in ultra-processed foods. Try to stick to unprocessed foods where possible within your diet. In my opinion a 90/10 or 80/20 ration between unprocessed and processed foods is achievable and a sensible target when considering your diet needs to be sustainable and long-term.

Over and out!