Originally Posted by PoorInRichfield

TL;DR
Is a high carb diet used by the majority of athletes good for one's long-term health off the bike or is this a "high performance despite the long-term health risks" diet?

Almost all articles I've read and videos I've watched on cycling nutrition are focused solely on performance on the bike, but few of them talk about the impact of a high carb diet on one's health in terms of heart disease, diabetes, etc. I don't doubt that "carb the f#$k-up" will help win races, but is this a good dietary lifestyle for long term health off the bike?

The Long Story
I started on the journey of becoming "fat adapted" several years ago. I.e., I started eating more food high in "healthy fats" as opposed to high carbohydrate foods as well a intermittent and longer duration fasting (3 - 7 days w/o food). I don't go so far as to say I have a ketogenic diet, but certainly eat more nuts, avocados, olive oil, butter, etc., than I used to eat. Initially, I was seeing no real benefit to this new high fat diet. I was still hungry a lot and nothing changed when riding my bike. It was a year later that I started noticing changes... and was a little freaked-out. I started realizing that I no longer felt hungry all the time, I wasn't feeling sleepy shortly after eating a meal, and what was the most interesting was that I was able to ride my bike on 60+ mile rides w/o bonking and hardly any food at all (Heck, I've never "bonked" since eating more fats.). I'm assuming this meant that it took a while for my body to become "fat adapted"... i.e., it could use either carbs or fat as a fuel source.

The core reason I opted to start eating more fat was the observation that so many people are obese and dyeing of heart disease and type 2 diabetes... and doing so at younger and younger ages. The research I've done points to this health crisis to be the result of a high carb, low fat diet that's been sold to us as being "healthy" for the past 50 years or so. As much as I love cycling, I only care about being fast on my bike if it actually is improving my health. Being the fastest cyclist on the planet that dies at age 50 isn't of interest to me. I'd rather be moderately fast and live a healthy 80+ years of age. I can't help but think that dumping high amounts of carbs into the body, despite the reason, will have the same results long-term... i.e., insulin resistance and potentially Type 2 diabetes and cardiovascular disease.

Most of the videos I've watched regarding cycling nutrition that state that a high carb diet is the way to go feature relatively young cyclists in their 20s or 30s. It's also apparent that the focus is on winning races and being fast, not necessarily on being healthy. When one is young, you can put just about anything in your body and it'll work, but as one ages, suddenly some of the habits of one's youth start to catch-up with you.

If you've experiment with high-fat diets and high-carb diets, what are your thoughts? Is the high-carb / high-performance diet of most athletes sustainable and 'healthy' or simply a "performance at all costs" diet?