I wholeheartedly disagree.
I used to struggled with weight most of my young years. No matter what I did I achieved incremental advances at best. At some point I decided to start "counting calories", something that I used to frown upon.
To my shock some foods that I ate that I considered "healthy" weren't so much so. This isn't even counting the fact that most experts can't even agree what is healthy or not, and opinions change over time.
Just like with coding, there are some black/white examples where the average person could make an easy distinction, but then there is a wide range of greys in the middle where people might not really know what's "good/bad".
For example, I would label peanut butter as a healthy snack, but you really need to keep an eye on your portions because it is wildly calorie dense and excess calories is usually unhealthy.
I think I'd prefer a standard nutrition label, since I'd guess that a mushroom battered in almond meal and deep fried in olive oil is probably made of three green ingredients but will end up red in combination.
If I have a “healthy” 300 calorie salad before a 3 hour run, I will crash very hard. Instead I will eat a high sugar and high fat candy bar.
If I have two “healthy” 800 calorie quinoa and chickpea salads when I am trying to lose weight, I will gain weight. Instead I could even eat a 500 calorie burger and lose weight.
Frankly if you are interested in your health, you have to understand how it all works. Sometimes you need carbs, sometimes you need fat, and sometimes you need protein. The amount that you need today depends on what you are planning to do this week. You need to know your own schedule and feed yourself accordingly.
Most of the “changing opinions over time by health experts” is because they are trying to answer “what one advice works for everyone” which is a non-starter question to begin with.
Some people genuinely don't know what's healthy and what's not. Some people know what's healthy but having trouble resisting these temptation. Usually it's a mixture of both.
As in, preferably taking as much vitamins and micronutrients as practical, with less calories than your body burns within reasonable range.
There might be a knowledge problem here, though: perhaps the author, a bit arrogantly, incorrectly assumed they understood the nutritionist’s ostensibly simple-minded intent and strategy on-sight, and dismissed it out-of-hand instead of considering its utility for differing goals, challenges, and motivations.
How many ingredients, how processed, amount of sugar/salt/worse etc.
As to traffic light systems: I think they should be transparent, and linked to easy-to-verify information.
An example of a good food one is the UK: They have a traffic light system for various macros. For each of the chosen macros (fat, sugar, etc...) the symbol displays the macro amount along with an associated colour.
This system is great because it is a systematic and consist visualization of an objective fact (e.g., more than 20 grams of sugar is always red). While the consumer might be influenced by the colour, it is extremely clear what the colour means and they can make up their own mind (e.g., how much fat do I want to consume?)
An example of a bad one: Germany has a traffic light system for food too. But here it is just a colour (with no clarity as to how the colour/rating is calculated). The rating seems arbitrary and strange (for example smoked salmon gets a red rating, while a slice of pizza might get a yellow rating, etc...). The consumer has no insight into what the rating truly means and hast to either trust it, or ignore it.
