Keeping Fruits Fresh...

Most fruits come in their own packages--apples, bananas, clementines (I love clementines so much more than oranges--so easy to peel, and super sweet!). Try putting a bowl of fruit out on the table, just a couple of each (apples & bananas together will cause the bananas to ripen faster), with extra stored elsewhere, separately. For cut apples, after you cut them, dip them in a little water with a few drops of lemon or lime juice, or even Sprite, and the citric acid will prevent browning.

If your in-laws like their junk food, try setting aside a cupboard especially for them (and, bonus, you can make it seem like you're thinking about them), and keep the stuff in there with the door closed, so at least it's not staring you in the face. Or, get a small storage unit and have them put it in their bedroom.

Check out your frozen food section. Usually there are a couple of varieties of frozen fruits, like strawberries, peaches, blueberries, mangoes, etc. We use these _a lot_ to make smoothies (peach, mango & OJ and some plain yogurt; 1 cup of berries + 1/2 cup milk & 1/2 cup of plain or vanilla yogurt, etc., blended in the blender), and you can freeze the smoothie in popsicle containers for a yummy treat.

For cut fruit, like melons, get the smallest you can get, so it'll be eaten up quickly after you cut it up.

R.,
To maintain the look and freshness of your diced fruit, you must eat it the same day you cut it. I like to add a bit of canned fruit like pineapple chunks or mandarin oranges. The juice has preservatives that will keep the fresh stuff really well! Just toss to coat and drain off the excess.
Otherwise, you can add a bit of lemon juice to your apples to keep them from going brown, but again, it shouldn't be sitting in the fridge for more than a day.
I like to make fruit salad like this:
1 large banana, sliced 1/2 inch thick
1 green apple, diced into chunks
2 handfuls R. grapes
1 small can mandarin oranges, drained
1 handful strawberries, hulled and quartered
1/2 can pineapple chunks
1/4 cup chopped walnuts

You can split this up into two servings (breakfast and afternoon snack), adding the walnuts right before you eat. It's so tasty and makes you feel healthy! If you want to get crazy with it, you can always add a bit of lime zest.
As veggies go, I stay away from nuking them. Steaming and boiling is a much better alternative. Instead of adding salt which makes you retain water weight, add fresh or dry herbs like my faves, rosemary and thyme. Garlic and onion add lots of flavor as well as any Mrs. Dash seasoning. Use butter sparingly and you'll be a smaller you in no time!
Feel free to write me for more ideas on how to prepare fruits and veggies. I love them!
Congrats on making a healthy life choice. Make sure to stay away from sodas and other sugary drinks. And drink plenty of water! Good luck!

Some fruits are definitely easier than others.
Apples - I'll just take a whole one with me or take apple sauce. Slicing ahead of time and trying to keep the slices from turning brown was always more fuss that I wanted to bother with.
Berries and grapes - I love these. They could not be easier. Bananas/peaches/apricots/plums are not bad as long as you can carry them without bruising them. Oranges and some grapefruit I'll either take one whole and peel it when I'm ready to eat or peel and separate the wedges earlier to take with me. I like cherries, but sometimes I don't like to deal with all the stems/pits.
Let's not forget about dried fruits and nuts. There are a large variety of trail mixes out there. Raisins, prunes, and lots of other dried fruits/berries are great too.

I usually eat my apples and pears whole, which is one way to solve this problem :) However I have heard that running cut (or bitten) apple under cold water will keep it from browning very much, that way you can keep it in the fridge all day.

Cantaloupe: I cut it in half,scoop out the seeds, and lay it cut-side down on a plate and keep it in the fridge that way. Then I just cut off a wedge as needed. It usually stays good for a week.

I also use FridgeSmart containers from Tupperware. They are kindof expensive (about $80.00 for a set of 4 containers) but they are made to keep your produce fresh longer. They have been totally worth it for me; I can keep lettuce perfectly fresh and crisp for up to 3 weeks. It has really come in handy with strawberries, blueberries and other fruits that tend to spoil quickly. I also freeze a lot of my chopped fruit, especially grapes (yum!) and then it is easy and fast to blend up a fruit smoothie (my favorite way to enjoy my fruit). Good luck!!

For apples, I use this stuff called Fruit Fresh. It is in a container similar to spices, and is usually somewhere by the sugar/jello or somewhere like that in the store. I slice up apples, put them in a ziploc bag. Sprinkle some of that on them, sort of mix it up, and they stay fresh for days (if they last that long). It works for other fruit too, and is maybe just a couple of dollars, but lasts for a long time. Lemon juice makes apples kind of sour. I do use pineapple juice or orange juice too--depending on what I'm making. We eat a lot of fruit, and the kids like the apples better if it's not brown for some reason! :)

Dipping cut apples and pears in Ginger Ale works too!

Pineapple juice works well to stop apples from browning without the tart flavor of lemon juice! No matter what you do though, your mix will taste better if prepared fresh.

The absolute best way to keep apples from browning after they are sliced (exposed to air) is to dip them in lemon juice. You can squeeze your own, or just use some from one of those little plastic lemons or whatever.

I slice the apples (usually granny smiths or braeburn, since they are already a little tart) into bite size slices. Put some lemon juice onto a small plate and take the pieces one at a time and lay them in the juice, then turn the other side into the juice. I always do this if I am making a fruit tray to take somewhere or setting out appetizers. It can sit out for hours and doesn't turn brown at all. I also do this for my kids to take to school in lunches sometimes.
I don't know what to do about kiwi or cantaloupe. (I don't eat cantaloupe, blech). But my husband does, and what he does is what I do with watermelon. Just cut it up into chunks and put them in a sealed plastic container in the fridge. Take out as needed to eat.

I've heard you can put lemon juice on the apple slices to keep them from turning brown. I chop fruit every morning for breakfast and for my husband to take to work. It stays fresh for a couple of hours. If I have half a canteloupe or pineapple left the next day, I cut off all the edges that were exposed to the air before I chop the rest.
If you like blackberries, raspberries, blueberries, strawberries, cherries, or grapes, put them in the containers ahead of time but don't rinse them until you're ready to eat and they should stay fresh. I like nectarines, plums, and oranges because there's no chopping involved.