Being on OW or ODSP is a poverty sentence that no amount of budgeting can change.

A single person with a disability receives only $979 a month on ODSP ($543 for basic needs, maximum $436 for shelter).
A single disabled parent with one child receives $1498 ($812 for basic needs, maxim $686 for shelter).
The Ontario average for a one-bedroom appartment is $787/month. For a two-bedroom apartment is $919/month.
Source: Income Security Advocacy Centre

There are approximately 675,000 people who receive social assistance in Ontario.
Special Diet Allowance program provides supplemental funds to recipients of Ontario Works and the Ontario Disability Support Program who have dietary needs related to a medical problem. People who met the eligibility requirements as certified by a health professional (physician, nurse practitioner, nutritionist, or midwife) could access from $10 to $250 per month depending on their needs.
Source: Registered Nurses Association of Ontario