The Big Fat Truth About Low Fat Foods on the BBC

black and white portrait of Zoe Salmon

Zoe Salmon

In February 2011 the BBC showed a documentary called The Big Fat Truth About Low Fat Foods which examined the diet food industry and looked at what goes into low fat foods, and asks if it is healthy.

For the documentary model and television presenter Zoe Salmon went on a 30 day “low fat” diet as an experiment. She simply has to eat low fat food for 1 month, anything can be eaten so long as it is labelled low fat or reduced fat and is processed.


Started out not knowing if the diet will result in weight loss or gain. As most people go on low fat diets to lose weight, the assumption was that she would also lose weight. Zoe showed concern about health of a diet high in processed foods.

Her current diet is simple, uncontrolled but without much processed food or junk food. She enjoys eating fresh fruits and always cooks for herself. She dines out a lot in nice restaurants but never opts of small meals – always meats, vegetables and desserts. She even enjoys weekly pizza parties with friends and drinks alcohol when socializing.

The “Low Fat Diet” had no fruit and vceg in the diet. She noticed several problems while on the diet.

The first problem was that all the food she ate was bland so she wanted to snack more and was constantly looking for satisfaction elsewhere. The low fat foods just were not pleasing her taste buds and there was never a message sent to the brain to say “I am now content”.

The documentary took a look at specific low fat diets too, including the Special k diet. They talked to people who stayed on diet for 7 years, eating 2 Special K meals a day. A problem highlighted with a Special K diet is high in sugar and low fiber and this leads to increased bowel disease risk and cancer risk.

Zoe soon noticed that she started eating more as low fat was not filling her up. She had low fat cereal bars for breakfast, but one bar was never enough. She also noticed that they sugar content of the so called healthy fruit drinks was higher than the sugar content of many carbonated soft drinks that she drank.

The healthy vitamin water that she was given to drink had 23 g of sugar in each bottle, a massive amount of sugar for a health drink.

Diet Coke is most the popular diet drink in the UK. The documentary looked at some people who drink 2 liters a day. This is really unhealthy as too many sweeteners, caffeine is bad for health, excess citric acid causes tooth decay, phosphoric acid leads to poorer bone health, and the aspartane sweetener, which is 200 times sweeteer than sugar, has been linked to brain tumors and in some studies, although the research is no conclusive at present.

Also studies have shown that drinking low calorie drinks results in you eating more food. One nutrition researcher, Catherine Appleton, did an experiment on rugby players. She provided one rugby team with a sugar based soft drink and another team with a low calorie drink, and then let them lose on a buffet. They had to record everything they ate.

The result was that the players that drank low sugar drinks ate 142 calorie more – they simply craved more food – the drink left them wanting to eat. The body expects energy after drinking a low calorie drink but does not get energy so hunger comes back sooner.

Week 1 Health Problems

After 1 week on a low fat diet Zoe Salmon felt lathargic, down, bloated, and her stomach felt fat even before she had dinner. She described herself as feeling “sluggish, tired, quite sick, cold coming on, sore throat, cannot think straight”.

Alice Sykes, a Harley Street nutritionist said that they lack of fat was affecting her brain. We need dietary fat to make brain work, fats are actually needed for many functions in the body.

So what replaced the fat?

Next the documentary asked the question, what replaced the fat in the low fat processed meal?

The answer is Methyl cellulose, which is a thickener, extender and stabiliser. Some foods contain 3 types of cellulose. Methyl cellulose is very similar to wall paper paste. It is sticky and not very healthy.

Duck Feathers in Bread

Another shocking discovery was that food manufacturers put L-Cysteine, also known as E920, in bread to replace natural fats. L-Cysteine is made from duck feathers in the UK, and in China it is extracted from human hair. Suddenly “low fat” food does not seem such a sensible option.

Week 2 Health Assessment

By week 2 Zoes bowels were no longer regular and she felt very sluggish. Her nutritionist recognized that there was almost no insoluble fiber in her diet as a result of only eating processed foods.

To find out more they visited Dr. Jeff pearson from Newcastle University. He analyses the digestion of food with some clever apparatus the mimic the human digestive tract.

He started by advising that Zoe was only getting 8 to 10g of fiber each day, although the recommended daily allowance of fiver is 24 g. This does not help digestion and can lead to bowel problems.

They examined a ready meal next. What was most surprising us that the meat in the ready meal broken down very quickly. The processing meant that the body did not need to work to digest it, so it passes through very quickly, which is one reason for increased appetite on a processed food diet.

Generally all low fat foods digest very quickly. This means that glucose is released into the blood quickly, and the theory is that these sudden glucose swings leads to late onset type 2 diabetes.

Low Fat Makes You Greedy and Lazy

Into the third week Zoe noticed that she was becoming greedier. “I turned greedy”. She found that she needed to eat much more often to manage her hunger, which meant she was taking in more calories.

Lethargy Caused By Processed Low Fat Foods

Zoe spoke to the Australian actor Sam Clark (best known as Ringo Brown in TV soap opera Neighbours) at an event. He had been touring on the road for many months and living off microwave meals. He too said that he was feeling very tired and really missed fresh food. The processed foods simply make you lethargic, and being lethargic means that you do not want to exercise. This often causes weight gain.

High Salt Content in Processed Salads

Zoe decided to grab a salad from a “health food” takeaway. The producers allowed this as it was packaged and also claimed to be low in fat. However, even though this was very tasty, it was not healthy. It was very high in salt.

Research has shown that 1 in 10 ready made salads have more salt in them than a Bigmac. You can find 8g salt in some salads which is about 50% than the total daily recommendation for salt consumption.

Usually Zoe eats lots of salads, but many of these are freshly made and therefore contain lower salt. Ready made salads have preservatives to keep the leaves from going off too soon.

The Salt Health Risk

Salt leads to increased blood pressure, strokes and heart disease. Around 75% salt we eat comes from processed food. Processed food needs salt and stabilizers to increase its shelf life.


Conclusion of the Low Fat Diet

Zoe’s one month on the Low Fat Diet did have one positive effect, it improved her B vitamin and antioxidant levels, both of which were noted as being a little too low. However, that was the only positive.

Zoe said that the one month on a low fat diet had been a struggle, a real battle, and she was very pleased when it was over. The lack of control over what goes into your body was Zoe’s greatest problem. She spent her life cooking healthy meals so always knew what she was eating. With processed foods it was always unknown.

When her nutritionist asked what surprised her most about the diet, she said that it was that processed food just does not taste nice. She is used to the wide range of flavors of fruits, steamed vegetables, meats and other foods that are still close to their natural state.

Did She Lose Weight on the Low Fat Diet?

The biggest question came last, and question everyone wanted to know the answer to. Did Zoe Salmon lose weight while on a one month low fat diet? No, she gained weight. In one month she gained 3 pounds while on a low fat diet. Low far diets just do not work and are not healthy.

This documentary was produced and directed by Ceri Aston for the BBC.

BBC Resources on Weight Loss

Photo Credit: Wikipedia / Austen Lennon

More like this in the Diet and Nutrition section

Leave a Reply

Your email address will not be published. Required fields are marked *