Some context: A "low carb diet" is defined as "A daily limit of 0.7 to 2 ounces (20 to 57 grams) of carbohydrates." A "keto diet" "typically reduces total carbohydrate intake to less than 50 grams a day and can be as low as 20 grams a day.... an average of 70-80% fat from total daily calories, 5-10% carbohydrate, and 10-20% protein." While there is some overlap between a keto diet and a low carb diet, they aren't the same thing.
A food is generally considered "low carb" if it isn't high in carbohydrates. Said another way, foods considered "low carb" tend to have more protein and/or fat that carbohydrates or their carbohydrates are mitigated by fiber, creating minimal "net carbohydrates."
"Net Carbohydrates" are "the carbohydrates in food that you can digest and use for energy. To calculate net carbs, take a food's total carbs and subtract: fiber."
Am I a proponent of a low carb or keto diet? Not necessarily.
I personally eat a good amount of carbohydrates, though mine comes in the form of whole steamed potatoes, baked winter squashes, oats, millet, lentils, mung beans, strawberries, and brown rice on occasion. I eat almost no pasta, sugar, bread, or baked goods.
I feel my best eating a diet that is primarily vegetables, with natural carbohydrates added in to sustain my natural physical and mental activity. (I move alot and think alot so my brain and muscles need glucose to perform).
However, not everyone has my body (and even my body has changed in the last 10-15 years with age and illness) so a lower carb diet may be what someone else needs (e.g. diabetic, over 50).
The only diet I'm a proponent of is a minimally processed, whole food diet, ideally one that is entirely (or primarily) plant-based, meaning centered on food from the produce section of the market.
WHAT PLANTS you put on your plate dictates if it's a high carb or low carb variation of this. Both are doable, both are healthy.
In the list below, items that are "low carb" could be suitable for a very low carb diet (e.g. keto) because they have very minimal net carbohydrates. The "lower carb" options are lower carb than what they are being compared to (for example, black rice has lower carbs than white rice; red lentil pasta has less net carbs that white pasta) but these items probably would not work for for a severely low carb diet (e.g. keto).
Items are listed in order of least processed (most whole food) to more processed, with deference given to items that are widely available and/or are inexpensive.
GRAIN-FREE, LOW CARB, KETO PASTA SUBSTITUTES:
seaweed noodles (e.g. kelp noodles)
heart of palm noodles (e.g. palmini)
dried squash noodles (e.g. solely)
tofu noodles (e.g. shirataki)
LOWER CARB PASTA SUBSTITUTES: pasta made from red lentils, black beans, chickpeas, split peas, quinoa, (or a combination) generally have lower "net carbs" compared to traditional grain-based pasta (e.g. whole-wheat, brown rice pasta).
GRAIN-FREE, LOW CARB, KETO RICE & QUINOA SUBSTITUTES:
celery root "couscous"
heart of palm rice (e.g. palmini, ontrue)
add Alchemy Fibre for Rice
Banza's chickpea-based rice
TVP (textured vegetable protein)
Konjac rice (e.g. Better than Rice)
LOWER CARB RICE & QUINOA SUBSTITUTES:
Note: Black rice also has the most protein and least amount of calories.
LOW CARB, KETO SUBSTITUTES FOR DICED POTATOES:
LOW CARB, KETO SUBSTITUTES FOR MASHED POTATOES:
Mash Celery Root
LOW CARB, KETO SUBSTITUTES FOR FRIES:
Celery Root Fries
Brussel Sprouts (roast)
LOW CARB, KETO SUBSTITUTES FOR ROASTED POTATOES:
roasted bell peppers
LOW CARB, KETO SUBSTITUTES FOR CARROTS & SWEET POTATOES:
colorful bell peppers
LOW CARB, GRAIN-FREE SUBSTITUTES FOR CROUTONS:
baked cubed tofu
LOWER CARB, GRAIN-FREE SUBSTITUTES FOR CROUTONS:
LOW CARB, GRAIN-FREE KETO SUBSTITUTES FOR BREAD, WRAPS & TORTILLAS:
collard green wrap
serve over greens
serve over cauliflower rice or cauliflower mash
coconut-flour tortillas (e.g. siete)
keto bread (e.g. orowheat, franz)
keto tortillas (e.g. Mission)
LOW CARB, KETO SUBSTITUTES FOR BEANS:
Nuts (e.g. walnuts, cashews)
Seeds (e.g. sunflower seeds, pepitas)
LOWER CARB SUBSTITUTES FOR BEANS:
black soy beans
Bean-Free Refried Beans (recipe on happyherbivore.com)
wheat gluten (e.g. seitan, no evil)
LOW CARB, KETO SUBSTITUTES FOR HUMMUS:
nut butters (e.g. cashew butter)
tahini (sesame seed paste)
Bean-Free Hummus or cauliflower hummus (recipe on happyherbivore.com)
vegan unsweetened greek yogurt
vegan unsweetened coconut yogurt
LOWER CARB SUBSTITUTES FOR HUMMUS:
vegan cream cheese
LOW CARB, GRAIN-FREE KETO SUBSTITUTE FOR FLOUR (1-2 TBSP) IN RECIPES:
LOWER CARB SUBSTITUTE FOR FLOUR (1-2 TBSP) IN RECIPES:
chickpea flour, garbanzo flour
OR omit and let it be runny
If it's being chilled (not heated) flaxseed meal, chia seeds, and psyllium husk powder may work.