We all want to eat healthily, but it can often be hard to determine the healthiness of a food item at a glance. For example, Diet Coke has 0 calories and 0 fat, and yet we all know more than the occasional can is a fast track to obesity.
Whilst
Reference Intake (RI) bars don't fully alleviate the issue, they do provide an easy way of assessing the health values of a product at a glance. With an intuitive red / yellow / green system along with percentages, finding out the health value of most foods is far easier. Lest ye forget, the body needs small amounts of sugar and fat, so aiming for all green bars all the time isn't necessarily the best option.
However, the system relies on predetermined portion sizes, which are often not realistic. For example, a loaf of bread will use a single slice to calculate the RIs, whereas almost every use of bread will require at least twice this portion. Unhealthy products are often not represented fairly, with RIs calculated off small slices of the product instead of the larger portion size most will have. This inconsistency, if spotted, further illustrates how absurdly high in fat and sugar cakes and chocolate can be. If 1/5th of a small cake contains 50% the daily allowance of saturated fat, imagine what half the cake would contain!
Additionally, the reference intakes don't distinguish between different types of sugar and fat. So whilst a banana contains a high amount of sugar, it is still an extremely healthy food, and far better than any crisps / chocolate. Nuts also suffer from high amounts of fat (and saturated fat), but in small amounts are very good for the body.
In summary, RIs should be used wherever possible to assess the benefits of a product, but may not tell the full story. Instead, they should be used to begin assessing the health benefits of a product, along with the ingredients list.