A lighter backpack makes hiking easier, especially on long or steep uphill treks, and will lessen the strain on your neck, shoulders, back and legs.
Over the past few years the trend has moved more and more to "light backpacking" with lighter materials and multi-purpose gear and equipment helping to cut the weight for hikers and backpackers. Here are some simple suggestions that will help you to lighten the load on the trail.
Reduce The Amount You Pack - Instead of taking several days of clothing for a multi-day hike, take one extra set and rinse out the dirty set as needed. Try to plan meals that you can prepare with a minimum of cookware, preferably one pot. Look for ways to be ingenious and take less "stuff".
Share - This will only work if you're trekking with at least one other person, so if you're a solo hiker skip this tip. Still here? Ok, if you're backpacking with a partner (or 2 or 3), figure out a way to share the load. This can be done in a couple of ways. First, split up equipment (tent, stove, etc.) among those hiking so that one person does not have the bulk of the gear weight. Second, figure out which equipment you can share, such as cookware, utensils, flashlights and even personal items like toothpaste, insect repellant, sunscreen, etc.
Replace - This will be an ongoing process where, as old equipment wears out, you replace it with more modern equipment that is built of lightweight yet durable material. Over a period of time, you can reduce the weight of gear in your backpack without losing functionality.
Multi-Purpose Your Equipment - The more uses you can find for one piece of equipment, the better. That trekking pole you use during the day to help you walk makes an excellent support for a tarpaulin at night. The pot you cook in makes a usable bowl to eat from. A poncho that protects you from the rain can also make a good awning to provide shade. See how inventive you can be in coming up with multiple uses for equipment and gear.
Measure And Repackage Food Stuff - For a 2 day hike, there's no reason to haul a full box of salt. Measure out what you anticipate needing into a mini zip-loc bag, available at some grocery stores or at crafting supply shops. Never take a box of anything; remove the contents from the box and place them in a quart or gallon sized zip-loc bag. That box is just extra weight that you'll have to haul back out.
With a little attention to your gear and equipment, you can easily reduce the weight of your backpack and lighten your load on the trail.