Today's system that is used in the UK is called the traffic light system. It is totally inadequate and misinforms you of the actual carbohydrates. It ONLY shows sugar but omits the carbohydrates. It is almost a lie about a product and this needs to be highlighted and the law changed.
On a keto/ low carb diet you should not consume any food which has more than 5 grams of carbs per 100 grams. (There are exceptions). Corn flakes has got 84% per 100 grams.
However let's look at below "food", very common breakfast cereals.
According to the traffic light system any product which contains 22.5 grs of sugar or above per 100 grams, is shown in red. This is a warning. To understand a product fully, you need to look at the nutritional value per 100 grams. Also understand that sugar content as well as carbohydrate content ARE THE SAME!! Yet manufacturers are only obliged to show sugar. OK, some people will now say that sugar and carbs are not the same, because there are complex, refined carbs as well as fiber. Yes agreed, however, and this is the bottom line, when carbs and sugar enter the blood system, they are now combined and called glucose. Some carbs will take slightly longer to increase insulin release, but they will still increase this, and especially "foods" shown below, it will just take a few minutes longer.
Kellogg say an average serving of 30 grams has 2.4 grams of sugar. But it also has 24.1 carbohydrates. In total this is 26.5 sugar per their recommended serving, minus fibre. Through evolution the adult human body is designed to cope with 15 grams of sugar a day, spread over 24 hours. Less for children. Not referring to recommended daily intake by the NHS, since recommendations from the government, regardless of food product is based on recommendations set 30-40 years ago and are totally wrong, hence the obesity epidemic we are now encountering.
Sugar content (aka carbs) in these common "foods" per 100 grams unless other size stated
Kellog's Corn flakes 84%
Kellog's Crunchy nut
corn flakes 82%
Tesco corn flakes 85.2%
Morrisons corn flakes 84.2%
Kellog's rice crispies 86%
Wholemeal toast 49.2%
White toast 56.2%
Half a baguette
Walker's crisps ready salted 51.6%
Sensations Thai sweet chilli 59%
Pringles sour cream & onion
Walker's baked crisps ready salted 69.2%
Kettle mature cheddar & red onion 52%
PASTA medium portion 180g cooked
White pasta 56.7%
Wholeweat pasta 52.2%
RICE medium portion 150g cooked
Basmati brown 43.1%
Don't forget carbohydrates ARE sugars, is soon as you swallow the food, the name changes again, to glucose. Confusing for many.
Some trivial information about John Harvey Kellog. Have a look and see what you think. The reason why Corn Flakes came about is because he wanted to stop masturbation and sexual pleasure. No this is not fake news, have a look at Daily Mail's article PRESS HERE