Earlier quoted context omitted.
I'm italian and I visited united states a couple of months ago. In my opinion the biggest problem is that you don't have decent food at affordable prices. Healthy food has nonsensical high prices and if you want something at a human price you don't have much choice except fast food. What a shame.
Healthy food isn't expensive. You can buy chicken breast for $3 to $5 a pound. You can buy a head of lettuce for $2. Oatmeal is dirt cheap. Most vegetables are less than $3 a pound.
Healthy food tends to spoil, and if you're not able to go shopping multiple times a week and have unpredictable availability for meal preparation, you're going to see a lot of spoilage. If 30% of your fresh produce ultimately spoils, your actual cost is 43% higher.
Healthy food requires a degree of planning and execution which takes time and focus. Finding healthy options which are appealing for 3x meals a day is a lot of work if you aren't happy with 1 or 2 standbys every day.
Healthy food is extremely hard to find on the go. If you don't have a kitchen at your disposal generally you are shit out of luck for finding something that is truly healthy. So for example, the quality of my diet is highly inversely correlated with the amount of travel I am doing in a given month.
Making unhealthy choices more expensive through taxes is extremely regressive for many of these reasons.