Ingredients to avoid on a low-carb or keto diet

1. Limit sugar

Few ingredients send our blood sugar and insulin on a rollercoaster like sugar. While some may be able to enjoy it in very small amounts, like in one or two squares of dark chocolate, we should otherwise try to eliminate added sugars from our diet.

Why are there so many names for sugar? This is one of the games that food companies play. If food manufacturers call sugar something else, you will be less likely to recognize it and more likely to buy.

Some food manufacturers will even use a couple of different kinds of sugar in a product so it will have less of each kind. That way, they can list the sugary ingredients farther down on the ingredient list, so buyers won’t know how much sugar is in there. Tricky, right?

What might sugar be called in the ingredient list on packaged foods?

Sometimes special sugars (other than sucrose) are listed by their scientific name. And sometimes sugar finds it way into your food as a natural ingredient, like maple syrup. So watch for these possibilities, too:

3. Limit industrial fats

All fats are not created equal. Reviewing the ingredient list on products at the supermarket — before you buy — can help you eat more healthy, naturally-occurring fat and avoid or limit industrial oils.

We encourage you to completely avoid artificially produced trans fats, usually listed as “partially hydrogenated” oil or vegetable shortening. These fats are banned in Europe and are in the process of being eliminated from the US food supply due to concerns about their health effects.¹

In addition, we suggest you minimize margarine and the highly-processed vegetable oils listed below. Unlike olive oil, coconut oil, and nut oils that are pressed and minimally processed, most vegetable oils are produced with high heat, solvents, deodorizers, and bleach.² These oils are high in omega-6 polyunsaturated fatty acids (PUFAs), which are less stable when heated.³ Finally, there are concerns that consuming foods very high in omega-6 fatty acids is at odds with our evolutionary diet, potentially leading to negative health effects (though this is controversial).⁴

Although there isn’t convincing data to show industrial seed oils are detrimental to our health, the evolutionary and mechanistic concerns are enough for us to recommend mostly sticking to the less processed, more natural oils and fats.

Read more in our guide — Vegetable oils: are they healthy?

Note that for avoiding trans fat, the ingredient list is a better guide than the nutrition facts label. Artificial trans fats may be present in small amounts, up to 0.49 grams per serving, and the nutrition facts label will still show 0 grams trans fat. Small amounts can add up, especially when serving sizes are small, so check the ingredients before assuming a product is trans fat free.

And you probably don’t need to worry about the small amounts of naturally occurring trans fats in whole foods like meat and butter.⁵ It is the artificial trans fats that we need to avoid.

Read more about fats in our guide — Healthy fats on a keto or low-carb diet. And while you are at it, why not check out our guide to eating more of the right kinds of fat — The top 10 ways to eat more fat.

More

There are two companion guides with more information about navigating the grocery store and deciphering food labels. They are:

Keto diet foods — top three mistakes at the grocery store 

How to use the nutrition facts label 

In addition, click through to our main keto foods guide, or our keto diet food list for real-food inspired grocery shopping!

For more basics, check out our simple but thorough beginner’s guide to the keto diet:

About the author

Jenni Calihan created the non-profit, Eat the Butter, to start a mother-to-mother conversation about diet and health. She advocates for real-food-more-fat eating, and has been feeding her family (four kids) for twenty years.

Practical low-carb guides

Dining out

How to eat more fat

Low-carb cheating

No cooking