Baby steps. They also recommend having at least half of the grains in a diet be whole grains.* For the best diet, both of these proportions should be as high as possible in most cases.
[0] https://www.cbc.ca/news/health/pizza-still-a-vegetable-for-u...
Real fruit juice is very much different from soda pop.
25g of sugar in 285g of juice[0] = that's 37 grams in 355ml of juice[1] vs. 41 grams of sugar in 355ml of soda[2], which is 110.8% more than the juice[3].
The half gram of fiber probably makes it little better, but it's still a very sugary drink.
[0] https://www.wolframalpha.com/input/?i=fresh+apple+juice+nutr... [1] https://www.google.com/search?q=25*(355%2F240) [2] https://www.pepsi.com/#!products/pepsi [3] https://www.google.com/search?q=41%2F37
I found this that seems like what the doctor said, but I'm not sure. Click on 'transcript' and read it.
https://nutritionfacts.org/video/if-fructose-is-bad-what-abo...
Edit: Other than this, fresh fruit juice contains minerals, vitamins, antioxidants etc etc.
The benefit of diversifying your diet (for example, by adding more fruits if you don't eat much of them) is to include nutrients that would otherwise be missing. Not just the macronutrients and micronutrients, but also other antioxidants such as polyphenols.[1]
The UK NHS recommendation touches on this briefly:[2]
> To get the most out of your 5 A Day, your 5 portions should include a variety of fruit and vegetables. This is because different fruits and vegetables contain different combinations of fibre, vitamins, minerals and other nutrients.
[1] https://en.wikipedia.org/wiki/List_of_antioxidants_in_food
(Alas, this morning I opened up the freezing while making a salad for breakfast and discovered that a housemate had left a massive ice cream cake in there, so I had no choice but to indulge.)
[0] https://www.myplate.gov/eat-healthy/fruits