Please refer to IRS publication 463 Travel, Entertainment, Gift, and Car Expenses - http://www.irs.gov/pub/irs-pdf/p463.pdf
To deduct your meal expenses - you should travel away from home for business to temporary place. You need to have you permanent place to be eligible for deductions.
Temporary job assignment would be if it is expected to last and actually lasted less than a year.
As that is your regular place of employment and it is lasted more than a year - you may not deduct any travel expenses.
Please let me know if you need any clarification.
You may deduct travel expenses - including lodging, per diem, and transportation expenses (mileage if you use your own car) - travel expenses are the ordinary and necessary expenses of traveling away from home for your business, profession, or job.
If you do not have tax home - and just moving to places where you job is - you may not deduct travel expenses. Generally, your tax home is your regular place of business or post of duty, regardless of where you maintain your family home. If you do not have a regular place of business or post of duty and there is no place where you regularly live, you are considered an itinerant (a transient) and your tax home is wherever you work. As an itinerant, you cannot claim a travel expense deduction because you are never considered to be traveling away from home.
If your assignment or job away from your main place of work is temporary, your tax home does not change. You are considered to be away from home for the whole period you are away from your main place of work. You can deduct your travel expenses if they otherwise qualify for deduction. Generally, a temporary assignment in a single location is one that is realistically expected to last (and does in fact last) for one year or less.
The company main office - may be considered as your main place of work - you do not need to convince me - I am on your side - as we are in the gray area - the question is - would the IRS agent agree with these argument in case of audit?...
If that is your main place of work - any other job locations would be considered as temporary and travel expenses would be deductible.
The standard meal allowance is the federal rate for meals and incidental expenses (M&IE). The rate for most small localities in the United States is $39 a day from Jan 1, through Dec 31, 2007. Most major cities and many other localities qualify for higher rates. The rates for localities within the continental United States are listed in Publication 1542. - http://www.irs.gov/pub/irs-pdf/p1542.pdf
If you used your car for business - you may deduct either actual expenses or use the standard mileage rate. For 2007, the standard mileage rate for the cost of operating your car for business use is 48½ cents per mile. please see for reference IRS publication 463 - http://www.irs.gov/pub/irs-pdf/p463.pdf