And on June 5, 1980, he looked at a group of his colleagues with the buttons of their vests straining through expanded waistlines.

“And I thought ‘I’m going to change my diet. I’m going to go to a high protein, low carbohydrate diet, lots of greens and lots of fish, and I’ve stuck to it.

“These guys will know,” he says, referring to a couple of staff sitting around the big table in his office, independent foreign affairs adviser Jon Johansson and press secretary John Tulloch.

“How many times have I had dessert? Once every two months, maybe.” They concur.

The interview was originally set up to discuss his trip to the United Nations in New York and Washington DC last week and his first meeting with Secretary of State Marco Rubio.

And he alludes to it in the survival discussion that followed the foreign affairs interview saying when his table received a plate of complementary pancakes at a diner in New York last week, he demurred, and he had a bowl of spinach.

“It’s delicious and very good for you and there, they were seriously generous.”

Peters says the drive to fix up the health system doesn’t count for much, especially with Maori and Polynesians, if they are not on good diets.

“Diet is not wealth. Diet is the right food…I think diet is absolutely critical.”

In his own family, there were 11 children and only one, David, has died – of cancer.

“We were infuriated with him because he wouldn’t go and get himself checked out regularly,” said Peters.

Of the 10 remaining Peters siblings, four are already in their 80s.

“There’s no family I know that is as lucky as us in that context.”

He puts it down to living frugally and eating a lot of home-grown vegetables and fish and home-baked bread.

“We used to moan and think we were really poor – we came to realise when we were older we were lucky.

“I think diet is absolutely critical and…the reality is I don’t think we can win this battle in terms of the health system in this country, Māori health changes, unless there is a massive dietary change.”

Peters’ mother lived to age 96 and his father to 85: “The only reason he died is he was too stubborn. He wouldn’t go to hospital because he thought he might die there.

“A lot of old Māori hate going to the hospital. I would have sedated him so much and put him there but by the time I found him it was too late.”

Peters said his other advice for survival is to keep yourself “fit and interested.”

“I’ve seen so many of my friends retire and they are dead now.”

He followed the good advice of former press secretary Frank Perry who had once said to him: “Winston, don’t act your age – and I’m not.”

“It’s no mistake that so many people live a long time who actually keep working, keep their minds busy, keep actively engaged – it’s the secret of success.

“The moment you give up in terms of working, I think it’s a very bad outcome. I’ve seen so many of my friends retire and they’re dead now.”

Peters does not plan to be in New Zealand for his birthday. He will be on his next trip as Foreign Minister, likely to be somewhere in the Pacific.

The Pacific has been his primary focus as Foreign Minister and last year, he travelled to all but one of the 18 countries in the Pacific Islands Forum.

Peters said that as well as inviting Rubio to New Zealand, he implored him to try to make it to the next Pacific Islands Forum in Honiara, Solomon Islands, where he could meet a lot of leaders face to face.

He said Rubio had wanted to visit New Zealand ever since hearing about his parents’ experience. They had stayed in Christchurch for two months with Rubio’s sister when her first husband had been working on a film set in New Zealand.

Rubio had been well briefed about New Zealand and former US ambassador Scott Brown had played a key part in briefing him.

In conveying New Zealand’s hopes for the United States in the region, Peters also expressed the hope that the focus of the first Trump administration on the region would be continued.

That was in defence and in aid for the Pacific, where a little bit of aid could go a long way.

“If two or three or four parties like us get together, putting less in but getting far more out, if things can be done with much greater efficiency, that’s what we have got to do.”

Before the Rubio meeting, Peters met with the head of USAID, Peter Marocco, and the National Security Adviser, Mike Waltz.

“We pointed out to them there were parts of the Pacific where if you were to be out there’s a serious vacuum there and we have to be seriously prepared for it – not that we expect you to be out – but it’s so critical that you are in.”

Peters did not have details or assurances from the US because things were still settling down, decisions were still to be made and many officials still to be confirmed.

USAID decisions, for example, were not expected until mid-April. And the policy of tariffs was still being formulated.

“Here’s the point; we had these very, very, very good discussions – very cordial, very warm – and we did agree that…we are going to up our dialogue going forward, and talk to each other all the time about these matters. That’s what we got assurance of.”

Rubio, a big fan of the Miami Dolphins, presented Peters with a gift of a pig-skin American football, with the official seal of the US on it. Peters was caught empty-handed having been firmly told that the Americans did not want gifts.

It was a punishing schedule in the United States and a faulty radiator in his hotel room kept him awake.

As soon as he returned to New Zealand, he headed to Christchurch to deliver a state-of-the-nation speech and he was clearly still energised this week by the turnout of 800 – and possibly by the protestors who turned up for it.

He reckons that when the crowd chanted “Out! Out!” to the pro-Palestinian protesters who had infiltrated the audience, it was reminiscent of Muldoon’s meeting at the Wiri Woolstore 50 years ago (although the crowd then was reported at 6500).

Peters is used to changing hats, and in just over two months, he will be taking one of them off altogether – that of Deputy Prime Minister – to hand over to Act leader David Seymour.

“When you take the job, that’s your No 1 responsibility.”

He volunteered several names of those he regarded as successful Deputy Prime Ministers: Sir Michael Cullen, who was deputy to Helen Clark, Sir Geoffrey Palmer, who was deputy to David Lange and Sir Don McKinnon, who was deputy to Jim Bolger.

In each case, they were deputy to a leader in their own parties. Peters has been Deputy Prime Minister three times and each time to a Prime Minister in a different party: to National’s Jim Bolger, after McKinnon, Labour’s Dame Jacinda Ardern and currently National’s Christopher Luxon.

Peters declined to offer any advice to Seymour. However, he agreed with the assessment that the job requires discipline.

“You need serious discipline because what has got to be imaged is cohesiveness and co-operation, not disunity, and that is what you are obligated to when you shake hands with somebody in that position.

“Mind you, it goes for the Prime Minister as well.”

There would be big differences in the policies of his party, New Zealand First, and where it went into in his first term of office, at a time when everyone the future.

“But right here, right now, our job is to form and make sure we have got a stable Government. That is what New Zealanders expect of us. It doesn’t matter whether they vote for us or not, they do expect stability though.”