I've spent a large amount of time studying health, so please forgive me for getting excited and writing so much. XD
I would take anyone giving health advice using absolutes ('all', 'every', 'always') with a grain of salt. The reason being that different people have different body types and won't necessarily see the same results using the same formula. Also,
there are 'good' and 'bad' sides to everything.* <---- very important to remember
* I know 'good' and 'bad' are subjective, but for this purpose it's referring to 'healthy' and 'harmful'.
Example:
Carbohydrates (sugars) can be good for you. They can be used for long-term energy supplies, short-term energy supplies, replenish glycogen levels, and are used to produce glucose to feed your brain.
But why then do you hear talk about carbohydrates/sugars being bad for you? It's because on the other side of the coin there are 'bad' uses that can harm the body. Highly processed grains, white sugar, refined carbohydrates, etc. These kinds of carbohydrates are basically
poisons that hold so little nutritional value that I can barely consider them 'food' and avoiding them like you would any other poison would be perfectly acceptable.
You can apply this to pretty much anything. Fats are good for your body because they're used for vital body functions... but you want 'good' fats that are from fresh food sources and aren't treated with chemicals. (Slightly off-topic, but a large majority of oil is treated with chemicals and is then boiled destroying a lot of the health benefits of the oil).
Proteins are also an essential part of a diet, but so many people choose to eat 'denatured' proteins or take their protein from unhealthy sources of food. Over their life-time the unhealthy substances build up n the body and cause health problems which result in a poor quality of life and degenerative diseases that often results in a slow and/or painful death.
tl;dr
Eat what you enjoy!
I advise making your choices from foods that aren't tampered with unnatural substances as much as possible.
Here are some interesting webpages I found on the subject:
What are Carbohydrates?
Weight Loss Resistance Due to Hormones and Toxicity