I’m eating lightweight backpacking food. I question what you are eating. 1+1/8 pounds is 18 ounces, correct?
One ounce of olive oil only has 251 calories (see http://www.fatsecret.com/calories-nutrition/usda/olive-oil?portionid=42185&portionamount=1.000 ). If you did nothing but drink olive oil, your maximum daily calories would only be 18*250=4,500, which would barely be enough to hike 15 miles.
If you ate only peanut butter, which is an excellent hiking food, you’d only get 94 calories per ounce, which would 18*94=~1,800. That would barely be enough to sit at a desk all day.
If you just at Snickers bars, it would be 140 calories per ounce (see http://calorielab.com/foods/candy-bars/108 ). 18*140=~2,500 which might be enough to hike 5 or 6 miles.
Personally, I aim to get a mixture of food that averages 100 to 120 calories per ounce. I aim to eat between 32 and 40 ounces of food per day. That gives me between 3,200 and 4,800 calories.
Backpacking costs me 572 calories per hour (see http://www.nutristrategy.com/caloriesburnedwalking.htm ), which means that a 15 mile haul at 2.5 miles per hour burns about 3,500 calories. Plus, for the other 18 hours that I’m not backpacking, I’d need probably another 1,400 calories just being idle. That makes a total daily burn of nearly 5,000 calories for a 15 mile haul. I lose weight when I eat my 2 to 2.5 pounds of food which only gives me 3,200 to 4,800 calories.
So, I must ask you, what is it that you eat when you only carry 18 ounces of food? Just olive oil? Otherwise, you must be incurring a daily calorie deficit of at least 2,000 calories which means you’d lose nearly a half-pound per day!
Loup