My dad was overweight, and he was dying of a liver disease. He was not a drinker.

He died eight years ago.

We’ll backtrack from there.

I loathe being preached to. Whatever the subject, whatever the reason. If someone preaches to me, I turn the other way. Much like sales. When I’m being sold, a sense of being manipulated kicks in … and I politely end the conversation.

I was a salesperson myself. I’ve been guilty of the same thing. But I digress.

One of my closest friends has long been a practicing vegan. We’re talking the full deal here: a strict plant-based diet, and no clothing or accessories made of animal products.

“Joel, my buddy,” he would say, “You’re getting too heavy! You need to be vegan!” Once again. Well-meaning but the same old.

“Enough, man,” was my usual response. “If I decide to do it, I’ll speak to you.”

The truth is, he cared. As did my dad. I was, in fact, fast becoming my dad’s twin. We had always looked alike. But I was up 50 pounds and counting from what my own doctor called my “healthy weight.” Towards the end of his life, my dad and I looked more like brothers, though I was 23 years his junior.

Two weeks before he passed, he advised me to not make the same mistakes he made. “You need to watch your weight,” he said.

The following day, in his hospital bed, I told my dad I was proud to be his son. He responded, though he could by then barely speak, “And I’m proud to be your father.”

I cried for weeks thereafter. I still do. But following my dad’s funeral, I promised my mom, who was also very worried about me, that I would do my best to lose the weight.

I called my friend. “Without preaching,” I said politely, “Can you explain to me exactly what you do?”

One week later.

I began my new “diet” on February 1, 2011. I cut out all meat and dairy. I would eat tofu and lentils for protein to start, and at least one of my three meals daily would be a salad. I missed my sushi, but veggie sushi was readily available. I did not work out a whit. No physical activity that first month, but only because I was lazy.

I went to the doctor. “You told me you weren’t going to weigh yourself.” I told him exactly that. “You lost 20 pounds.” I was stunned. I was feeling better, in truth, but I was truly surprised. “I want to take some blood work,” he continued. “Want to know your blood pressure?”

“I guess.”

I was on blood pressure medication, which had not served me well. “120 over 80,” he said.

“You’re fucking kidding me,” I blurted. I was used to 150 over 100, or thereabouts. “Seriously?”

“Seriously. Come back in another month. Let’s see where you’re at, but let’s get some blood from you now.”

I followed the same routine for the next 30 days. I went back to the doctor. “You lost another ten pounds,” he said. “However, doing what you’re doing is working for you … Come back in another month. Your blood pressure is 117 over 78. Depending on what happens, we’ll take you off of both your pressure medication, and your statin.”

Did I say I was on a statin for high cholesterol? I was. The next month, I was down another five pounds, and my second round of blood work exhibited a cholesterol read that was more than satisfactory.

“Get off your meds entirely,” the doctor told me. “Maintain and you’ll be fine. Good job.”

And that was that.

My dad would have been so proud. My mom was thrilled. My friend was validated.

And I was feeling pretty damn good about myself.

Though I looked upon my efforts initially as a “diet,” it turned out to be a lifestyle change. Now, I still wear leather — I’m working on it — but the thought of eating any animal product at this stage in my life is anathema to me. I can barely stand watching the annual Thanksgiving Turkey Pardon even, as I believe all turkeys have a right a live. Yeah, it goes there with me these days. I do not believe in the efforts of big-game hunters, who kill for trophy. I’ve become an animal activist, of sorts.

And, as to any meats or dairies I’ve loved before? All of it can be mimicked with food made from plants.

But, all that said, I believe there are exceptions to everything. Various ailments have not been proven to subside by virtue of a plant-based diet. Many dieters, frankly, believe they need their meat and I will never preach to them otherwise.

I can only express here what has worked for me. Now, in truth, I’ve since gained much of my weight back. Why? I’ve become addicted to vegan eating, and I simply eat too much.

I’m working on that too.

I will say this, though: A vegan diet does work, but a) referring to such a thing as a diet is paying the potential benefits a true disservice, and b) the undertaking, if prudently followed, must be a lifestyle change.

Speak to your doctor first if you are considering such a lifestyle change, and check back with me later for your results.

You’ve heard this expression before: “The life you save may be your own.”

You’ve heard this one as well: “Don’t fucking preach to me, and I just may listen to you.”

As ever, I wish you all the best …