I've been a devoted of fan of cookbook author, speaker and food activist Mark Bittman for decades. I eagerly awaited his columns and op-eds in the "New York Times," armchair-traveled with him on his epic PBS road trip across Spain and religiously planned my meals from his How to Cook Everything cookbook series as a fledgling home cook. And although his recipes and culinary adventures expanded my palate and improved my cooking skills, his 2009 book "Food Matters" changed the way I think about eating.

Back in my high school and college days, being a vegetarian gave me some cred as a card-carrying member of PETA, but didn't do a whole lot for my overall health. Plant-based pickings were slim and dinners out at my favorite budget-friendly haunts quickly led to consolation orders of French fries, pasta, grilled cheese ... and more fries. The "veg" part of vegetarian was notably missing and I gained weight.

So I went back to my meat-eating ways — joining the low-carb, high protein revolution as a way to shed the pounds and it worked. Although maintaining my weight was easier, I still had that nagging feeling (let's call it guilt) that all of the meat, cheese and eggs I was eating couldn't be good for me — least of all for the animals who made the earthly sacrifice to fuel my low-carb lifestyle. Which was precisely Bittman's simple, but important point in "Food Matters": the way we eat isn't good for us, the animals we're rely on or the environment we live in. In fact, the way we eat is unsustainable.

Bittman's "Vegan Before 6:00" philosophy was just the answer I was looking for. All day, I'd follow a vegan diet (focusing on real food, mostly fruits and vegetables) and then relax things a bit later on at night. So, if I wanted a piece of salmon, a little piece of baguette and a glass of wine, that was okay. After three months, I was eating more fruits and vegetables than ever before and had lost 20 pounds in the process.

The benefits of being a part-time vegan

Bittman was following the science, of course. Studies show that eating a vegan diet, chock-full of antioxidant- and fiber-rich foods, like fruits, vegetables, whole grains and legumes, may reduce your risk of cancer. And adopting a plant-based diet can lead to improvements in blood pressure, reductions in heart disease, and a lower risk of developing type 2 diabetes.

So much as changed since my vegetarian days back in the 1990s and eating a plant-based diet is easier than ever. But you don't have to fully embrace a vegan lifestyle to reap some of these benefits — just eating fewer animal products and boosting the number of plant-based foods you eat every day can lead to many of these positive health improvements.

I sat down with Mark Bittman to talk about Vegan Before 6:00, what science tells us about how we should be eating and why we just can't seem to believe what health experts keep telling us.

This interview was edited and condensed for clarity.

What's wrong with the way we eat?

MB: One of the interesting things about the way we eat is that — to the extent that we eat badly — it's bad for our personal health and it's also bad for the environment. A happy coincidence is that to the extent that we eat well, it's also good for the environment.

What we mean, generally, by "eating well" is eating real food. And real food — you know what real food is. We all know what real food is. It's generally food that doesn't have labels. It's generally food that's actually nourishing. It's generally food that you recognize as food.

The problem with the standard American diet is that we eat a lot of highly processed food. We eat way more saturated fats than we ought to, and we eat more sugar than we ought to. We also eat more industrially produced meat than we ought to. So, if we cut back on all of those things and focus on real food, our health gets better and we're less likely to develop chronic diseases. But we're also having a more positive impact on the environment so we lower our carbon footprint.

Right now, we seem to be obsessed with protein, most of which is animal-based.

MB: You know, we may seem to be obsessed by eating too much protein in this country, but our obsessions go from one obsession followed by another. So now we're obsessed with, "Do I get enough protein?," or, "Do I eat too much gluten?," and so on, when really the answer is as the best nutritionists and dietitians have been saying for 100 years. The answer is a balanced diet.