Sunil Chhetri seems to have been able to crack the riddle and turn back the clock, especially in terms of his fitness. The 35-year-old is the Indian national team's scoring mainstay and that responsibility involves a strict diet and fitness regime.

Diet discipline did not come automatically to the striker. He remembers a time during his early playing days when portion control or restrictions were not priority. His regimen today is a different story.

"My diet has been improving. It’s not like I was as strict as I am today some 10 years ago. However, 10 years back, I wasn't eating anything and everything either. As every year passed by, I kept making changes- being strict on myself," Chhetri told AIFF's official website on Saturday.

"When I was 25 and I was told to eat six pieces of potato every day, some days it would be eight, others it would be 10 - not like it was going to make a big difference. But now, when my nutritionist tells me that you get to eat six pieces a day - it's six. Done," said the skipper.

"These things really help you when you grow older because by now you have understood what works for you, and it’s easier to be more disciplined. That's probably when people who are 30 plus do well," he added.

Chhetri, who has the second-most international goals among active international footballers, revealed that he his stint with Sporting Lisbon back in 2012, helped him pay a little more attention to his diet.

"The awareness crept up after my stint with Sporting Lisbon. When I was in Kansas in the US, there was a little slight change but as I said as I was young – I didn’t go deep into it. I followed it but not religiously. Then when I went to Sporting Lisbon, I saw that it’s common in Europe - the caution about what they eat. It was there that I became stricter."

Chhetri revealed that his interactions with experts over the years have helped control his desire to cheat on diet.

"As I grew older, and met more people who could help me, I kept making those positive changes. And because I was getting older, it was easier to calm my desperation, or my desire to cheat on diet," he said.

The Indian captain also spoke about adapting to a vegan diet which includes forgoing meat and diary.

"I have become a vegan - I don’t take dairy or meat. It has helped me a lot in terms of recovery and digestion," Chhetri said.

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However that didn't stop the Bengaluru FC striker from letting his guard down on sweets twice in the recent past.

"It’s been over one and a half years. I have indulged on two momentous occasions," he revealed. "The first time I gave in was after BFC won the Hero ISL; and the next time I had a bite was after we drew our away match with Qatar. You need to understand what works best for your own body. In fact, there have been occasions when people put slices of cake in my mouth. But I never gulped it, but went to the washroom to rinse out," he said with a smile.

Chhetri also spoke in detail about the support he receives from his wife, Sonam, who keeps him company despite not being a vegan.

"Does she (Chhetri's wife) eat what I eat? Well, of course. Not because she has to, but because she gives me company. But yeah, she is not a vegan, and every now and then, she enjoys her prawns, and fish curries too. The support from home though has stayed the bedrock," Chhetri said.

When asked if staying away from tasty food has made things boring, Chhetri shrugged off the proposition and said,"I don’t feel the desire or feel bad that I am missing on something."