More than 46,000 elderly people have had their "meals on wheels" service axed in the past three years, according to the Malnutrition Task Force.
Analysis of official data for England shows the number of people receiving meals has fallen from 75,885 in 2010/2011 to 29,605 in 2013/14.
Spending on meals on wheels for people aged 65 and over has fallen 47%, from £42.1 million in 2010/11 to £22.3 million in 2013/14.
This equates to thousands of pensioners losing out at the same time as social care services have been cut, the taskforce warned.
In less than a decade, the numbers receiving meals on wheels has fallen by more than 80% - equating to 125,000 older people.
It comes as the number of elderly people admitted to hospital with malnutrition continues to rise.
Figures from the Health and Social Care Information Centre for England show there was a 34.2% increase in admissions for malnutrition between August 2010 to July 2011 and August 2014 to July 2015.
In the last year, admissions for malnutrition were highest in the 50 to 59 age group for women and the 60 to 69 age group for men.
The British Association of Parenteral and Enteral Nutrition (Bapen) estimates that 1.3 million aged 65 and over suffer from malnutrition, with many living in their own homes or in the community.
Diane Jeffrey, chair of the Malnutrition Task Force and chair of Age UK, said: "Ensuring older people are well nourished is essential if they are to stay fit and well, and meals on wheels have traditionally played an important role in this.
"It is dismaying to see this former mainstay of community care for older people being allowed to shrivel away because of Government cuts. At this rate of decline there won't be any meals on wheels provision left at all in a few years' time.
"An important preventive service for older people is well on the way to becoming extinct.
"This seems a terrible false economy, since the meals on wheels service helps to prevent malnutrition, which makes older people more vulnerable to illness and disease and piles cost on to the NHS, as well as spelling misery for the individuals concerned.
"Meals on wheels also provide essential social contact for those pensioners who are otherwise entirely alone, an important indirect benefit."
The Malnutrition Task Force is an independent group of experts from health, social care and local government aimed at preventing malnutrition in older people.
It is backed by the charity Age UK, the Royal Voluntary Service, Bapen and the meals and nutrition firms Apetito and Nutricia Advanced Medical Nutrition.
Councils have the power to work out who needs meals in their area, together with whether they will subsidise them or whether people are charged.
Figures from Age UK show that spend per head of population on meals on wheels is falling.
In 2010/11, the average cost per person per year over the age of 65 was £4.92 per head.
But this had dropped to £2.40 per head in 2013/14.
Age UK estimates there are about 300,000 people aged 65 and over in England who need help with eating or have difficulty eating unaided.