Dr Eva Orsmond is urging the Government to follow the example of Boris Johnson in encouraging the population to shed the pandemic kilos.
The TV doctor believes the nation is sleepwalking into a worsening obesity crisis during the lockdown.
International studies are showing Covid-19 weight gains of more than two kilos in France and Italy, while an American study found one in five people put on between two and 4.5kg, due to extra snacking at home.
"Everybody is talking about the famous Covid stone," Dr Eva said.
"French people put on an average of 2kg of weight over the pandemic and I think in Spain it was between 3kg to 6kg.
"I didn't put on weight. I was in Portugal but it was because I was seriously working on it.
"There were those who got focused and lost weight - but we are talking about the majority of Irish people, who probably put on weight. Some 60pc were already overweight or obese before Covid-19."
Dr Eva, who has a master's degree in public health, says the Government needs to urgently highlight the issue as studies show obesity is a risk factor in coronavirus cases.
A study published last week confirmed obesity is linked to higher odds of Covid-19 hospital admission.
"We had a serious epidemic before and now everything is concentrated around the pandemic, but we need to tell people there is a serious link with the worst outcome of Covid-19 and obesity," she said.
"At least in the UK, Boris Johnson has actually mentioned something about the [population] being overweight or obese.
"I haven't heard any of the [Irish] ministers say anything about overweight or obesity. They should fight, not just against Covid, but against overweight and obesity and make the link of worse outcomes in overweight and obese people.
"All the international data suggests it is going in a worse direction and this pandemic hasn't helped."
The obesity specialist, who has weight-loss clinics in Dublin, Cork and Galway, also urged the Government to highlight the importance of vitamin D, which plays a key role in the body's immune response to fight infections like Covid-19.
Australian vitamin D researchers say a study on 30,000 people shows it reduces acute respiratory tract infections.
It is estimated one in eight Irish adults under 50 is deficient in the sunshine vitamin - while just over a quarter of over-70s are estimated to be deficient in Vitamin D, which comes from the sun and various food sources.
"Vitamin D deficiency is another thing that has been linked to Covid-19. Who is talking about vitamin D deficiency?" the doctor said.
"I took blood the other day from one of my patients, and his vitamin D was 20nmol/l - it should be over 80nmol/l.
"There are so many things that can help people to build their immunity, because this Covid-19 is clearly not going away. It is basically trying to learn to live with the disease in a different way and getting people's immunity stronger," she said.
She believes strong immune systems are protecting people from the virus.
"Many people who have it are asymptomatic because they have a good immune system," she said.
"I wouldn't be surprised if I had it because I hardly ever get the flu - I seem to have a very good immune system. But I look after my immune system. I actually work on it.
"WHO says 80pc of the cases are mild or asymptomatic. All the restrictions are killing the country's economy, and with the economic and psychological damage it creates, it is foolish thinking we can eradicate the virus."
"We need to learn to live with the virus and work on making people healthier with healthier immune systems," she added.
During the past few months, the high-profile doctor has wondered why the Government couldn't have tackled the obesity crisis in a similar way to the pandemic.
She said: "I have been thinking all the way through this Covid crisis on how much money has suddenly been found for unemployment benefits and all these different supports.
"How is it possible that we never found the money to give people the right [weight loss] advice and proper weight-loss clinics?"
Before the pandemic, she said 10pc of the health budget went to the treatment of Type 2 diabetes.
"Type 2 diabetes is a total lifestyle-related condition - 99pc of people with Type 2 diabetes are overweight or obese," she added.
She said it is worrying that young people who are socialising are eating one or more meals a night in the pub under current guidelines.
"This whole situation must be very bizarre for younger people, who are used to meeting friends.
"Some young people might be careful and eat nothing during the day and maybe they go out and don't gain weight, but 25pc of children and teenagers are overweight and obese.
"And 70pc of obese and overweight teenagers remain obese as adults."
Prevention is the key component in the fight against obesity, she said.
This is why she believes it is so important to hammer the message home to children at a young age and to their parents.
She said: "We have to start with children because once you get somebody overweight and obese, it's much more difficult to correct. It's difficult if you don't get parents on board."
She warns hospitals will be overrun if the national waistline keeps expanding.
"Coronary vascular diseases are the number one killer and then cancers and Type 2 diabetes, but they are all linked to lifestyle."
She added: "Weight is not easy to lose, but it can be done as my patients seem to be able to do it."