What about a chickpea snack? Make at home or ready made?
Crunchy Chickpeas

My local natural foods grocery just started carrying these and they seem perfect:
Primal Bars

The same company also makes some great chicken jerky products. Google Caveman jerky.

If you're going to be doing a lot of walking I wouldn't worry about calories as much as long as you're keeping your low carb macros in line (I'm guessing its just for a few days) - nuts, jerky, etc. but the best thing to do really is focus on having filling meals so you don't have much need for snacks. If your hotel room has a fridge there are plenty of low carb foods you can keep there.

Grain-based fruit & nut snacks tend to give me indigestion. I like cheese sticks - low fat mozzarella. They can get a bit soft w/o refrigeration, but they are cheese & isn't it supposed to be eaten @ room temperature anyway? Calorie & protein-wise, 1 stick is about equivalent to an egg. Red or black grapes or cherries is my other go-to. I put the fruit in a disposable plastic box so it won't get squashed in my purse or bag. For some reason, those 2 items keep me satisfied & not hungry for hours.

I prefer on-the-go foods I don't have to touch w/ my fingers when out & about & grapes & cherries have stems & cheese sticks have wrappers. Cherry/grape tomatoes might be subbed for the sweeter fruits; I'd pack a few toothpicks w/ those.

--Add chia seeds to your drinking water to make a version of Chia Fresca. Chia seeds will help keep you feeling full, give you energy, and aid in keeping you hydrated. We use chia seeds in a whey-based lemonade when we work outdoors.
Ingredients for one glass:

• 12 oz. cold, fresh drinking water
• 1 large lemon (it should produce about 3 tablespoons of juice - you can also use packets of True Lemon, True Lime, or True Orange or other no-calorie drink mixes to flavor the water)
• 2 teaspoons sugar or sweetener of choice (skip if you add a sweetened drink mix)
• one teaspoon chia seed

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

--Make your own trail mix.

--Celery sticks and to-go container/s of peanut butter. (One 1.5-oz. Jif To Go has 11 g. total carbs and 9 g. protein

--Pumpkin Breakfast Cookies - http://leelalicious.com/pumpkin-breakfast-cookies/ (substitute part of the rolled oats with Hemp Hearts for additional protein and use 1/3 c. of cranberries - chopped fine or snipped with kitchen scissors). Wrap individually (tightly) in plastic wrap and then place in a plastic container or zip-lock bag.

--You'll find lots of recipes at the Keto Diet Blog like this one:

Keto Cheesy Party Crackers- http://ketodietapp.com/Blog/post/2015/12/29/keto-cheesy-party-crackers

--Low Carb Cheese Crackers- http://lowcarblayla.blogspot.com/2012/02/cheese-crackers.html

I've made these with different cheese slices than just American cheese - jalapeno, smoked cheese, cheddar, etc. I've also used other sliced cheese products besides Kraft Deluxe American Cheese, even though many of the instructions on-line say to use Kraft Deluxe.

-Grainlady

With 90 degree weather and so many wonderful delis in NYC, why not take a break and have a drink and a snack. If not, maybe make up your own version of trail mix.

A couple peeled hard boiled eggs in a container: filling, no carbs, not messy.

i would just take some small apples.

I work every day in NYC and the five boroughs for the past 20yrs. It is a bit hot but not like heat 90 outside of town. It is coastal and can get a bit breezy and walking the shady side of any avenue is much cooler. Pop in any store for AC.

I always have a snack in my NYC 'life' bag. We all have a sturdy bag that has just about every need. I like the Chia bars. Always a couple with me. Tiny and have had one or two for a couple months now...a good 'gorp' mix i make always a new blend. Best to have something you are familiar with.

Do check with your hotel and ask if they have a in-room small fridge with that tiny top freezer...tell them you have medication that needs to be kept cool. We freeze and use recycled water bottles that i put a couple tea bags in and a slice of ginger and a slice of lemon, (no sugar) but that is optional if you need sweet....i carry the frozen h2o and plain unfrozen water in a lunch fabric foil lined bag,(forgot the brand name...) It keeps any veg snack cool all day and water is from my filtered reverse osmosis sink tap. Water is over-priced everywhere as most forget the need.

With a google search near where you are staying, i bet a great grocery is nearby. Even google 'organic veggies' and a good treat is near.

Pretty standard that 'city people' carry their own veg snack and h2o so we do not need to rely on 'tourist trap' high priced water. Or over-priced snack bars.

Amazing that with so many markets and good food all over the city, i find when you need a bite and feeling 'peckish' only junk deli crap is handy. Most of those do have a good hundred or more of the so popular snack wrapped bar type things.

A smart phone is so handy. Plan your day trips with a google search and seek out the best hot spot for a good cheap meal to relax for an hour. Download Waze and get familiar if you don't have it. (it is free). Just about any part of town has incredible hidden finds for very few dollars. Locals know the good spots and do 'yelp' reviews.

Water is more important for city running around. Never buy from a street vendor. Gross to mention but i've witnessed cute little ladies filling used water bottles with a nasty garden hose, then adding a dab of glue to the cap to sell from a cooler later. Yuck. NYC water is really good, but not from a used water bottle.

Not sure what your plans are but if you want some great spots in areas of the city for a good bite to eat i'll be happy to provide some hints....like ChinaTown. etc.

Wow do i ever take that back. Hot soup in the city it is so humid. Not the Big Apple....calling it the Baked Apple. Spent the day down on WallSt area and Battery Park last night....still cooler in the shade.

I agree with the suggestion to bring a little gorp/trail mix, which is what I do for a day in the city. Mix a small handful of nuts with some seeds if you want (e.g. pumpkin, sunflower), throw in a few raisins/craisins, and can "stretch" it with a little "healthy" cereal - like Arrowhead Mills. Put it in a little snack bag, and you are good to go!

Nuts are always good. Don't have to keep them cold, very healthy, tasty, satisfy hunger, and readily available. Add a little dried fruit if you want.

Original question is asking for diet-friendly snacks not too high in calories. Trail mixes & nuts, tho very nutritious, are notoriously high in calories...

I'll bet pattysue has some terrific ideas:

http://ths.gardenweb.com/discussions/3988606/kaw-im-really-enjoying-my-kitchen?n=28

Epic makes excellent protein bars and I like their bacon bites too. BARE makes crispy dehydrated apple chips regular and cinnamon flavored.

Raw zucchini spears, baby carrots, dill pickles and hard-boiled eggs would be my choices.

I know that nuts are high in calories, but they're filling, too, and very nutritious. I wouldn't discount them based solely on calories.

I can't add to the already good ideas of veggie sticks, cheese, and boiled eggs (except, how do you keep them chilled while walking around?), and fruit such as grapes.

Sally

"how do you keep them chilled while walking around?" If you carry bottled water and can freeze it in your hotel refer, it will slowly thaw to drink and keep your snack cold until eaten. Those little round red wax coated cheeses in individual sizes aren't great, but they would not spoil in a day and are low carb.

Many of the suggestions I don't understand as low carb...not apples or dried apples or other dried fruit or grapes, trail mix or cereal?

Dried roasted soybeans are pretty low in carbs, high in protein and 120 cals in 1/2 cup.

I've sure "walked the city"...not only NY but Venice, Madrid...well you get the idea. Never felt the need tor food to sustain me between meals.
Eat a good breakfast, with some protein and that ought to carry you to lunch. Stop for lunch....and perhaps youw ill want to stop about 4 to grab an iced tea and find a bench to sit on the drink it, and you ought to be able to make it to dinner without falling flat from hunger.

Well, we surely all have different systems with different needs and preferences, but just because YOU wouldn't need a snack, doesn't mean someone else doesn't. I don't have much of an appetite for breakfast until later in the morning, so it's a problem when traveling and I NEED some protein mid morning. Also, when traveling, it's sometimes not convenient to grab a meal on the dot, so maybe a snack to tide her over is needed. OP asked for ideas of snacks, not suggestions that she just suck it up until lunch.

The point about eating protein for breakfast is a good one, IMO. I find that a breakfast of 20 grams protein or more ( 2 egg cheese omelet, for instance) plus fresh fruit plus green tea can keep me from getting hungry for hours. Still a good idea to have snacks on hand too. Better to have it & not need it, than need it & not have it, after all...

Honestly, I'd ditch the diet and be all over the street food. :-)

There are also health concerns for some people, diabetics need regular "snacks", as do those who are hypoglycemic. Ashley has found that since her stroke she needs some protein every couple of hours, just a bite or two, to keep her from getting migraine headaches. Even barring health issues, sometimes after a filling breakfast I don't want lunch at all, but about 2 pm I want a small snack, just to keep me until supper.

So, filling but low carb snacks that won't spoil in the heat? Jerky has been mentioned, although it can be high in sodium. I've seen roasted edamame, and hummus would stay OK in that pack with a frozen water bottle, if you decided to do that. I've seen protein "chips", and a low carb wrap with a cheese stick would stay well enough, I think. Yogurt might be another possibility, and I used to send celery sticks with peanut butter to school, just fill the celery with the nut butter and put the two sticks together like a sandwich. Raisins in the middle if you like. I also make "energy bites" and homemade protein bars for the kids, Bud especially tends to gobble junk if there's nothing else readily available.

Be sure to have fun!

Annie

Freezing a water bottle has never been an option in a hotel room fridge-- no matter where I have stayed.

Another snack that I traveled with is a single serving size of Justin's Almondbutter. It's not super low calorie but I found that keeping one in my purse as I explore a new city is very helpful. There's fat, protein and it's filling too.

I've not used the Justin single serve but see them. Like little 'ketchup' packets.

I've had a fridge in probably the past few dozen hotels with a small top freezer. Most memorable to not have one recently. We do seek out more boutique hotels over the chain variety. I use TripAdvisor for reviews. Most in NYC don't charge for the first couple bottles of water but do make money if you tap into the full fridge of beer and soda and snacks. (why i suggested to call ahead and ask). It is a money maker so many have them.

I had to clean out a fridge of soda crap to fit the giant Katz's pastrami i only ate one quarter of during a last winter snow storm...took it home to DH and noticed the water was complimentary so froze it to keep the meat beast cold.

I'm with Annie about issues with small snacks especially in the heat. My food need goes way down and just need a bit of small protein or tiny bits during the day. No big meals. Need water.

Nothing worse that getting peckish and spending time looking for a mini snack. Having something small in your bag familiar is much better than looking for it. Fine dining while traveling is one thing but sometimes the sites to see are most important and food can often just be about 'fuel' for getting from one place to the next.

This post made me check my 'city' bag. Some things have been in there for months. I don't even chew gum but for some reason have some. The 'Krave' jerky is really good. All over the city now. Even in a pharmacy that seems to be on every corner now. Probably expensive but i get promo cases and hand it out to the homeless usually.

I'll be all over WallStreet tomorrow and i just need fuel and water not a restaurant. My work provides that but as a visitor i would want the same....

I had a similar experience in Rome and Florence - we walked a lot and never felt the need for snacks, but we did carry water with us. We always made a point of having a very filling breakfast, and that carried us through to lunch. Most of the time we were too distracted to think about eating, but we did go to the rooftop restaurant at the Uffizi Gallery, since we spent four and half hours there, and that included lunchtime. I found water to be a pretty good appetite suppressant, except when there were restaurants around.