What makes processed food unhealthy?

Robert Lustig, a long-time researcher on childhood obesity at the University of California in San Francisco, has published a new editorial today (Jan. 23). It outlines ways processed foods can differ from unprocessed food.

Lustig also argued that processed foods had caused harm to Americans in four areas. These foods have increased the consumption of refined carbohydrates, obesity, type 2 diabetes, and harmed the environment. He also wrote that Americans had been forced to spend more on their health care.

Lustig explained that processed food is defined by the food engineering involved in making them. According to Lustig, processed foods meet the following seven criteria: Mass-produced, consistent from batch to batch and use specialized ingredients.

Lustig said that defining processed foods using these engineered properties does not reflect the nutritional differences between unprocessed and processed foods. Continue reading to find out what makes processed foods different.

Too little fibre

Lustig stated that processed food is less fibre than unprocessed foods.

Fibre is essential for health as it plays an important role in food absorption in the gut. According to the editorial, fibre forms a gelatinous barrier in the intestines covering the intestinal walls.

This barrier reduces glucose and fructose absorption in the blood. It helps to prevent spikes in blood sugar. According to the editorial, slow food absorption gives gut bacteria more time for food digestion. The compounds that gut bacteria produce can be beneficial to the body by helping to break down food.

Insufficient omega-3 fatty Acid

The editorial stated that processed food has too many omega-3 oils.

Lustig explained that the body converts these fatty acid compounds, which can be found in foods like fish and nuts, into compounds called eicosapentaenoic Acid, and both have anti-inflammatory properties.

Too many omega-6 fat acids

Lustig argued that processed foods have too many Omega-6 fatty acids.

Although these fatty acids are similar to omega-3s in their structure, they are converted by the body into a pro-inflammatory compound called Arachidonic Acid.

In the editorial, Lustig stated that omega-6 and omega-3 fatty acids should be ideally a one-to-one ratio. However, the average American diet has a 25 to 1 ratio, which favours an inflamed state. He wrote that inflammation could lead to oxidative stress and cell damage.

Too few micronutrients

Micronutrients are the insufficient vitamins and minerals found in processed foods.

Lustig explained that many of these micronutrients, such as vitamin C or E, act as antioxidants which prevent cellular damage.

Too many trans fats

Trans fats are another issue for processed foods, according to the editorial.

Despite new regulations being passed by the Food and Drug Administration requiring companies to remove trans fats from their food by June 2018, ingredients can still be found in processed foods.

Trans fat molecules have a structural difference from other types of fats like omega-3 and Omega-6 fatty acids. This is because of the double bond in the molecule, which makes it impossible for the body to break down trans fats. Lustig explained.

He wrote that instead, trans fats end up in the liver and arteries of people, where they create damaging free radicals.

Too many branched-chain amino acids

The editorial stated that processed foods have too many branched-chain amino Acids.

The building blocks of proteins are amino acids. The chemical structure of an amino acid is what the “branched-chain” part of its name refers to. Lustig explained that the body requires several amino acids, such as valine, leucine, and isoleucine, which have branched chains.

He wrote that branched-chain amino acids are necessary for muscle building, but excessive amounts can cause liver damage, which leads to excess fat.