7 mistakes I made going plant-based in my 20s that I tell everyone in their 40s to avoid

I went vegan at 35, not in my 20s. But I made every mistake a 20-something would make, because I approached it the way I approached everything back then: all or nothing, research-obsessed, and convinced that willpower could override biology.

Now, at 43, I've had nearly a decade to reflect on what actually works.

And when friends in their 40s tell me they're considering plant-based eating, I find myself saying the same things over and over.

Here are the seven mistakes I wish someone had warned me about.

1. I treated it like a diet instead of a lifestyle shift

In my finance days, I was trained to think in terms of optimization and outcomes.

So when I went vegan, I created spreadsheets. I tracked macros obsessively. I weighed my food. I treated my body like a problem to be solved rather than a life to be lived.

This mindset lasted about three months before I burned out completely. The restriction felt punishing, not liberating.

What finally worked was shifting my focus from what I was eliminating to what I was gaining: new flavors, new cooking skills, a clearer conscience.

Are you approaching this change with curiosity or with control? The answer matters more than you might think.

2. I ignored the protein learning curve

I'm not going to tell you that protein is hard to get on a vegan diet. It's not.

But I will tell you that it requires intention, especially in your 40s when maintaining muscle mass becomes increasingly important.

My mistake was assuming that if I ate enough volume, the protein would sort itself out.

I was tired constantly. My recovery from runs was terrible. It took me six months to realize I was eating plenty of carbs and fats but consistently falling short on protein.

Now I make sure every meal has a solid protein anchor: tempeh, lentils, tofu, edamame, or a combination. It's not complicated once you build the habit, but you do have to build it.

3. I announced it to everyone immediately

The week I went vegan, I told my parents, my colleagues, my running group, and approximately everyone I'd ever met. I was excited. I wanted accountability.

What I got instead was a lot of unsolicited opinions and a few relationships that became unnecessarily strained.

My mother, in particular, took it personally. She's from a generation where feeding people is love, and my new restrictions felt like rejection to her. It took us years to find our footing again.

If I could do it over, I'd have waited. I'd have let my actions speak before my words did. There's wisdom in being quietly consistent rather than loudly committed.

4. I didn't supplement B12 from day one

This one is non-negotiable, and I'm embarrassed it took me as long as it did.

B12 is not reliably available from plant sources, and deficiency can cause serious neurological problems. I spent my first year assuming fortified foods would cover me. They didn't.

By the time I got my levels checked, I was significantly low. The brain fog I'd attributed to work stress? Partly B12. The tingling in my hands during long runs? B12.

Please don't make this mistake. Get a quality B12 supplement and take it consistently. This is one area where "I'll figure it out later" can have real consequences.

5. I made perfection the enemy of progress

Early on, I discovered that a sauce I'd been using contained trace amounts of dairy. I spiraled. I felt like a fraud.

I questioned whether I could really call myself vegan if I'd accidentally consumed something non-vegan.

This perfectionism nearly derailed me entirely. The truth is, living in a non-vegan world means occasional mistakes. A mislabeled product.

A well-meaning friend who didn't realize chicken stock isn't vegetarian. These moments don't erase your commitment.

What matters is the overall direction of your choices, not whether every single moment is flawless. Give yourself the grace you'd give a friend.

6. I forgot that my body's needs would change

What worked for me at 35 doesn't work the same way at 43. My digestion has changed. My energy needs have shifted. My relationship with food has evolved as I've moved through perimenopause.

I used to eat the same breakfast every single day for years. Now I pay attention to what my body is actually asking for.

Some days that's a big tofu scramble with vegetables. Other days it's something lighter. The rigidity I once prized now feels like a limitation.

Your 40s are a time of transition in so many ways. Your eating should be flexible enough to transition with you.

7. I isolated myself instead of finding community

For the first two years, I didn't know a single other vegan in real life.

I read blogs and followed accounts online, but I ate alone at gatherings, brought my own food to parties, and generally felt like an outsider in my own social circles.

Finding community changed everything. A local running group with several plant-based athletes. A cookbook club that met monthly.

Even just one friend who understood why I cared about this made the lifestyle feel sustainable rather than isolating.

Humans aren't meant to do hard things alone. Whatever form it takes, find your people.

Final thoughts

Going plant-based in your 40s is different from doing it in your 20s. You have more wisdom, more self-awareness, and hopefully more patience with yourself.

But you also have established habits, social networks, and a body that's been doing things a certain way for decades.

The transition doesn't have to be perfect. It just has to be yours. Take what serves you from my mistakes, leave what doesn't, and trust that you know yourself better than any article ever could.

What's one thing you're worried about getting wrong? Sometimes naming the fear is the first step toward moving through it.