I would love to know the answer to this as well. I'm headed to my in-laws for a week, and we eat out most of the time we're there - and mostly at burger chains and that sort of thing. My stomach always implodes halfway through our trips with them because I can't handle all the grease!

I always find that a trip to the grocery store helps. We come back with seasonal fruits, nuts and snacks (for everyone) that hopefully help balance out all the other stuff.

We travel by car cross country and sometimes we just get caught in a food wilderness...we try to pick the best selections possible, even the lowliest chains have green stuff. Salads, get the potato altered so it has broccoli but not much cheese...do what you can. We do stop in supermarkets where we can and pick up already prepped salads, etc. things that don't need cooking all readily available in the prepared food areas, also get fruit. We have found that google is our friend if we can plan ahead in that area. On most smart phone's even without any handy foodie apps we can make use of google maps by searching for "restaurants near me" or restaurants near or in a named area. Many of the newer Starbucks now have some fairly good pick-up food in boxes or two of the breakfast selections, the feta wrap and the turkey bacon egg on wheat English Muffin are ok. They are available, as long as they have them left, all day, even if you son't see the display, ask. Einstein's has some better selections now on thin bagels...check websites for nutrition info, so you can make the best choices in the fast food places you may be stuck in. Good luck!

carry a big box of satsumas with you at all times.

Control what you can control, and try not to stress about the other stuff. Breakfast is usually manageable. Try to stick to something light or at least healthy here. Same goes for lunch. Save the splurge for dinner. Whenever we go out for dinner I always get a side salad with the dressing on the side and eat it before my meal. This fills me up a bit and prevents me from eating the whole rich/greasy meal. (most of the time.) Stick to water to drink. And if you can't control your food, at least try to get out for a walk each day.

Buy a tiffin and stock a few snacks that will curb your appetite before you get to your destination. Sliced fruit, cheese, veggies and wheat free crackers. Stop at a local store each day if you have to and find a place that makes smoothies and have a hard boiled egg in the morning with a few apple slices. Then make sure you control what is on your plate. Fish oil capsules and salads are a good bet too.

And I agree, go for a walk each day.

I have a grease-sensitive stomach, so I totally hear this. Here are a few ideas:

No-Fridge:
Multigrain Wasa Crackers
Avocados
Bananas
Cherry tomatoes
Whole, raw almonds
Coconut Water
Emergen-C packets
Ginger chews (great for indigestion and overfull feelings)

If you have access to a mini-fridge:
Hard-boiled eggs
Cheese sticks
Baby carrots

Notice that most of this is high protein and low-carb--eating out will result in carb overload no matter what you do. That can result in bloating and ick.

The avocado is fabulous smashed onto the Wasa Crackers--good for any meal of the day.

Both the bananas and the avocados are high in potassium, which will help to flush out extra water that you may be retaining from all the junk.

When Ordering Out:
*Try to avoid high-dairy and high-acid/ nightshade foods (tomatoes, peppers), because they can compound any heartburn issues caused by grease.
*Breakfast: Even the greasiest of diners can usually provide you with poached eggs and oatmeal--no danger there.
*Of the major chains, Wendy's seems to have the most healthy options--think, a plain potato, a side salad, and a yogurt. Not fascinating, but it works. If The Golden Arches is your only option come 1 AM, order a plain hamburger--you know, like the kind that come in happy meals. Mysterious and alarming, but relatively low-cal and low grease.
*Skip soft drinks and coffees--you'll need water, and more of it than usual.
*If you're ordering a sandwich, take off the top slice of bread and eat it open-face. Fewer calories, but more to the point, you're less likely to feel stuffed and bloated.

I hope all that helps!
Bad Mama Genny

This is a great question -- one that I think a lot of us struggle with. When I visit my partner's family, most of our organic/local/whole foods eating habits necessarily take a back seat, and I often leave feeling in poorer health.

As others have said, trying to get exercise every day -- even a few push-ups, crunches, one-foot balancing, and lunges before bedtime can do the trick! -- is a great way to combat The Ick.

Although bringing healthy snacks can be great, sometimes it feels a bit poncy or even insulting to one's hosts if you bring your own food. I find it's better to aim for the healthiest, whole-est foods available, limit the especially greasy or sugary or salty stuff, and don't sweat it.

Be your own advocate, too: sometimes family will suggest an especially indulgent place to eat out because you're visiting. Do a little research, be inquisitive, and politely express a preference for something "not too heavy". (Chinese, Vietnamese, or other Asian food is often a great bet because it tends to be vegetable-heavy and steamed rice is always an option. Even Panda Express has some relatively light dishes!)

Anecdote: at Thanksgiving, my partner and I were at his family's house and he let slip that I had recently started Weight Watchers. Although I was embarrassed, his sister was thrilled to say that she, too, was on WW! She and I traded some tips and recipes, and she helped me navigate some of the local chains and other options that weren't familiar.

I agree with fab - control what you can control. What I've been doing this year is, when I am able to "control" my meals (i.e. eating at home, preparing my own meals at someone else's house, snacks), I've been eating light, vegetarian-only meals. So maybe an egg and toast or bowl of cereal for breakfast, some whole wheat pasta with cottage cheese for lunch, fruits and veggies for snacks. That way when I end up at a Christmas dinner and gorge myself, at least I haven't been eating like that all week so the holidays as a whole don't take a huge toll on my body.