Just remember, with an INCH bag you are thinking over the long-term. You won’t be packing a lot of food but you will need to pack tools and equipment that will allow you to get or find food! Also, instead of bringing gallons of water you will pack the means of purifying water found as you are hiking to a destination. More things to consider:

Food and Protection, Snares, Slingshot, Fishing line/compact fishing pole and hooks, Crossbow:
As with water, you can only carry so much food with you, and after a few days it will be gone. While you could take some MREs or other lightweight and easy to carry food (e.g. freeze-dried), you should ensure you have with you the means to catch your own food. There are calories all around you if you know how to hunt and fish. Foraging will also supplement your diet with much needed plant nutrition.
By having a compact fishing rod or fishing line, you can catch fish that are highly nutritious. With snare wire and a slingshot, you can catch small game. With a crossbow, you can catch bigger game. Just make sure you get these things ahead of time and practice so you become skilled in how to use them.
Why not a gun? Well, you can and should certainly have one, but the bullets will eventually run out and then it will be useless. The fishing line and snares are reusable. Ammo for a slingshot can be found anywhere there are rocks (which is pretty much everywhere!). Arrows for a crossbow can be reclaimed and reused most of the time, and if you build your skills ahead of time, you can make arrows out of what is around you.

Medical
Have a serious first aid kit. Fortunately, first aid kits are already small, compact, and lightweight, so you don’t have to alter this much. Just be sure to pack what you can in as compact a package as possible.
But as with your other food and supplies, eventually the items in your first aid kit will run out, so you need to be familiar with how to identify medicinal plants and learn how to use what you find in nature to help you with medical care and procedures when necessary.

Tools
When you are surviving on the move, there are certain tools you will need in certain situations. The key is to take with you the fewest number of tools that will effectively get any job done that needs doing. You essentially need bushcraft tools that are easy to carry and effective for the many tasks you will need to perform, such as clearing brush, cutting firewood, and skinning and cleaning animals. Here are the basic tools you need:
Large knife
Small knife
Hatchet/small axe
Saw
Multi-tool
Carving tool
Whetstone
Firestarter
Navigation
Compass
Gas mask
Shovel (compact and foldable)
Small sewing kit

Clothing: When it comes to clothing, you need to have clothing for all weather situations. This means warm- and cold-weather clothing and waterproof clothing. However, you should pack one extra of each thing, not multiples. There simply is no room and you’ll have to get used to having less and washing what you do have in the nearest creek once a week or so. Just be sure the clothing you do have is high quality, moisture-wicking, and include some wool in there.

Shelter: Tents, tarps, sleeping bags, and pillows are all added weight that you don’t need, even if you might want these luxury items. If you have a high-quality bivvy bag, one that is like a tiny tent, you can survive quite nicely. Add your survival shovel for when you need to dig a trench to tuck down in and you are all set.
This is the basic must-have gear for an INCH bag, but you may want to include other supplies and equipment to ensure your survival. This is fine, provided you choose carefully and they will fit in your pack.

And there are so many other things to consider. Go to Modern Survival Online where they cover assembling and selecting the right INCH bag, as well as more information on what should go inside, carrying water, and important skills.

In the end, you need to be certain you have everything you will need in an INCH bag. Again, you are never going back home so if you simply bug out with the necessities, know everything you’ve left behind will never be recovered!

As always, work on your skills. Fish and hunt. Forage in the wilderness and learn what is good and bad for you. Read and become a good bush-crafter. This, with your INCH bag, just may keep you alive, giving you and your family a future!