Peaty won two gold medals at the Tokyo Games.
Adam Peaty wants the government to support elite athletes who can't pay their bills with patriotism.
Peaty gave his views on athlete support to the MPs.
The National Lottery funds UK Sport.
The government will get all the credit when we win a medal at the Olympics, said Peaty.
He told the committee that the government and the country get benefits.
We fly that flag very proudly, but we can't pay our bills with patriotism. I'm supported by other companies and sponsors, but more needs to be done by the government.
The government announced in August that it would be giving over seventy million dollars a year to elite Olympic and Paralympic programmes over the next three years.
One year before lottery funding was introduced, Great Britain returned 65 medals at the Tokyo Olympics compared with 15 at the 1996 Atlanta Games.
Peaty called on the government to improve its funding of grassroots sport to prevent the closing of leisure centers and said the lottery can only do so much.
He said he was not a politician. I know if you have a healthier nation, a fitter nation, a happier nation and a valued nation, that return on investment is going to be great.
The government and the lottery gave over 200 million pounds to support community clubs and exercise centers through the coronaviruses epidemic.
Kevin Brennan told Peaty that the National Lottery had increased its funding to good causes by two per cent between 2009-10 and 2016-17, when its profits had increased by 122 per cent.
Peaty said that if he looked at his company and knew what he was doing, he would feel morally drained.
It's disappointing to see people refer to an outdated, flawed report which gives an inaccurate picture of the current health of the National Lottery.
We keep around one per cent of profit. We achieved record National Lottery sales of over £8.3 billion and over 7 billion of that went back to winners and society, compared with £78 million retained in profit.
The profits for good causes have increased by over thirty million dollars a year since the third licence was granted in 2009.