Firstly, it is STRONGLY ENCOURAGED to keep track of your expenses using a professional software or app.
COMPENSATION ... as stated by the IRS:
S corporations must pay REASONABLE COMPENSATION to a shareholder-employee in return for services that the employee provides to the corporation before non-wage distributions may be made to the shareholder-employee. The amount of reasonable compensation will never exceed the amount received by the shareholder either directly or indirectly.
Reasonable Compensation is the value that would ordinarily be paid for like services by like enterprises under like circumstances. Reasonableness is determined based on all the facts and circumstances.
Compensation paid to employee-owners reduces the profit margin.
BUSINESS MEALS
Business Meals are deductible if they are: Ordinary and Necessary, has a Business Connection, Is NOIT lavish or Extravagant, the taxpayer or representative is present.
As for the lunches (food in general) you may deduct the lunches while on a business trip, but regular lunches by yourself while performing work is NOT deductible.
DEDUCTION OF VEHICLES
You CANNOT deduct the use of your personal vehicle(s) unless the S-Corporation holds title to the Vehicle (the Vehicle is in the business's name). You may deduct the per diem mileage of the vehicle if an Accountable Plan for mileage reimbursement is stated in the Operating Agreement of the Business.
OTHER DEDUCTIONS
These are some examples of other items you may deduct:
Advertising
Bank Interest and Fees
Computer and Peripherals
Education (training such as Medical Conferences)
Insurance
Office space
Office Expenses
Professional Services
Retirement plans
Subscriptions
Supplies
Utilities
