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3 Foods You Should and Shouldn’t Eat on a Keto Diet

3 Foods You Should and Shouldn’t Eat on a Keto Diet

Following the keto diet sounds simple enough: Just stay within 20 to 30 grams of net carbohydrates each day to stay in ketosis, with your protein consumption making up 25%, at most, of the total calories you consume.  Still, one of the first things people ask when getting into the keto diet is “What can (and can’t) I eat to stay in ketosis?”  Unfortunately, the problem begins when you start incorporating seemingly keto-friendly foods into your diet — foods which actually have ingredients that aren’t keto-friendly.   In other words, you may think you’re doing a good job of staying in ketosis, but you’re actually eating foods that keep you out of it.

There are plenty of resources online listing down which basic food groups you can include in your diet and which ones you should omit.  However, if you’re planning to be creative with your diet (i.e. find alternatives to foods which aren’t keto-friendly), you’re going to want to read this first.


3 Foods You Shouldn’t Eat on a Keto Diet

what you should and shouldn't eat on a keto diet


Avoid Gluten-free baked products

People who suffer from gluten intolerance logically eliminate its biggest source: wheat-based products.  Fortunately, not all bread and baked goods need to be made from wheat. Thus, gluten-free alternatives to popular food have increased in availability over the years.  Now, since the keto diet advocates keeping your carbohydrate consumption low, avoiding wheat-based products tends to be a given.  However, make sure not to commit the mistake of thinking that gluten-free baked goods are fair game!

Gluten-free breads, as well as cupcakes, cakes, and other baked products are ideal for people suffering from Celiac Disease.  However, they are still quite abundant in carbohydrates — in fact, their carbohydrate content may be even higher!   Gluten-free baked goods typically use flour made out of starches and grains, which tend to have a more rapid and powerful impact on your glycemic index.   If you really have a strong craving for baked goods, opt for products made with coconut flour, psyllium husk flour, oat fiber, or almond flour instead.


Avoid Diet Soft Drinks 

You’re probably thinking, “Wait a minute. The entire point of diet soft drinks is that they don’t contain sugar. Aren’t these drinks exactly what people following the keto diet need to satisfy their carbonated cravings?”  Well, not exactly.

While diet soda gets rid of the sugar component found in other fizzy drinks, it compensates for the taste with aspartame.  While it won’t knock you out of ketosis on its own, too much of it may trigger a host of other nasty problems in your system, such as headaches or even epileptic seizures.  This advice is especially important for individuals with epilepsy who use the keto diet to help with the condition.

Further, while the likelihood of citric acid — another abundant component of diet soda — taking you out of ketosis has yet to be definitively proven,  it won’t hurt to err on the side of caution.  


Avoid Mayonnaise

Now, this isn’t intended to prompt you to avoid delicious dips entirely.  However, when choosing condiments for your meals, a bit of discernment goes a long way.  For instance, mayonnaise is definitely keto-friendly.  Unfortunately, studies have shown that most come with a ton of health hazards as well.

Mayonnaise is often packed with trans fats and poorly-sourced saturated fats, which have been shown to be detrimental to your heart’s well-being.  A study published in the British Medical Journal affirmed that a higher intake of trans fats and saturated fats make it more likely for you to develop coronary artery disease.   So if mayonnaise is on the menu, reach for a mayonnaise that is high in heart-healthy oleic acid made from avocado oil, such as Keto Certified avocado mayonnaise from Primal Kitchen.


3 Food You Should Add to your Keto Diet



Get More Black coffee on your Keto Diet

Many people find themselves unable to function properly throughout the day without at least one cup of coffee, and with good reason.  As you already know, coffee is a rich source of caffeine. It has been shown to enhance your level of alertness, which in turn enables you to do better at your tasks. Coffee also improves your metabolic rate, making it great for weight loss.  The benefits of coffee don’t end there. Studies have shown an apparent relationship between increased coffee consumption and diabetes risk. In other words, the more you drink coffee, the more you reduce the likelihood you’ll suffer from diabetes. (Interestingly, the same can be said for tea.)

As if those benefits weren’t already enough, coffee has also been shown to lower your risk of critical diseases such as Alzheimer’s disease, Parkinson’s disease, and dementia. It can even make you feel happier; studies have shown that increased coffee consumption can reduce the likelihood of women getting depressed.  The best part? Coffee is virtually devoid of carbohydrates. Well, black coffee, at least. For keto dieters, it’s best to enjoy your coffee as is, without any taste-altering additives (aside perhaps from heavy cream, which is also keto-friendly).


Add Berries to your Keto Diet

You’ve surely read about how fruits contain enough carbohydrates to kick your body out of ketosis. Not even dried fruits are excluded from this. This is precisely why keto dieters generally tend to avoid fruits, especially the really sweet ones.  However, there’s one type of fruit you can consume without fear of getting booted out of the fat-burning zone: berries.  For starters, berries contain significant quantities of antioxidants, which improve your resistance against various diseases and reduce inflammation.  Strawberries, blueberries, raspberries, and blackberries are also famously low in terms of carbohydrate content. What’s more, berries have high amounts of fiber, which is great for proper digestion.


Dark chocolate is Keto-Friendly 

A highly recommended snack for the health-conscious dessert lover, dark chocolate can also be a keto dieter’s best friend.  Compared to other sources, cocoa and dark chocolate contain a proportionately decent amount of antioxidants, just like berries.  What’s more, the flavanols in dark chocolate can lower your blood pressure, thereby reducing your risk of heart disease.

However, there’s one thing you need to consider before embracing dark chocolate as part of your keto diet. You should stick to buying only the kinds of dark chocolate with at least 70% cocoa solids.  These contain only around 10 grams of carbohydrates.

While it’s good to have a basic knowledge of which food groups to avoid when going on a keto diet, don’t rely on your knowledge alone, especially when you’re exploring new options. As much as possible, look for information on the ingredients and nutritional content of any new food you’d like to add to your diet.  After all, there’s more to the keto diet than mere carb-counting.





  • Capriles VD, Arêas JAG. Approaches to reduce the glycemic response of gluten-free products: in vivo and in vitro studies. Food Funct. 2016;7:1266–1272. doi: 10.1039/C5FO01264C.
  • Lipton RB, Newman LC, Cohen JS, Solomon S. Aspartame as a dietary trigger of headache.  Headache. 1989;29:90–92. doi: 10.1111/j.1526-4610.1989.hed2902090.x.
  • Gaby AR. Natural approaches to epilepsy. Alternative medicine review. 2007;12:9.
  • Zong, G., Li, Y., Wanders, A.J., Alssema, M., Zock, P.L., Willett, W.C., Hu, F.B., Sun, Q. Intake of individual saturated fatty acids and risk of coronary heart disease in US men and women: two prospective longitudinal cohort studies BMJ. 2016;355:i5796.
  • Mensink RP, Zock PL, Kester AD, Katan MB. Effects of dietary fatty acids and carbohydrates on the ratio of serum total to HDL cholesterol and on serum lipids and apolipoproteins: A meta-analysis of 60 controlled trials. Am J Clin Nutr. 2003;77:1146–1155. doi: 10.1093/ajcn/77.5.1146.
  • Rogers PJ, Richardson NJ. Why do we like drinks that contain caffeine? Trends Food SciTechnol 1993;4:108–11. 7.
  • Dulloo A.G., Geissler C.A., Horton T., Collins A., Miller D.S. Normal caffeine consumption: Influence on thermogenesis and daily energy expenditure in lean and postobese human volunteers. Am. J. Clin. Nutr. 1989;49:44–50. doi: 10.1093/ajcn/49.1.44.
  • Ruxton CHS. The impact of caffeine on mood, cognitive function, performance and hydration: a review of benefits and risks. Nutrition Bulletin. 2008;33(1):15–25.
  • Odegaard AO, Pereira MA, Koh WP, Arakawa K, Lee HP, Yu MC. Coffee, tea, and incident type 2 diabetes: the Singapore Chinese Health Study. Am J Clin Nutr. 2008;88:979–85. 10.1093/ajcn/88.4.979
  • Van Dieren S., Uiterwaal C.S.P.M., van der Schouw Y.T., van der A D.L., Boer J.M.A., Spijkerman A., Grobbee D.E., Beulens J.W.J. Coffee and tea consumption and risk of Type 2 diabetes. Diabetologia. 2009;52:2561–2569. doi: 10.1007/s00125-009-1516-3.
  • Maia L., de Mendonça A. (2002). Does caffeine intake protect from Alzheimer’s disease? Eur. J. Neurol. 9 377–382.
  • Hernan M.A., Takkouche B., Caamano-Isorna F., Gestal-Otero J.J. A meta-analysis of coffee drinking, cigarette smoking, and the risk of Parkinson’s disease. Ann. Neurol. 2002;52:276–284. doi: 10.1002/ana.10277.
  • Santos C, Costa J, Santos J, Vaz-Carneiro A, Lunet N. Caffeine intake and dementia: systematic review and meta-analysis. Journal of Alzheimer’s Disease. 2010;20(Suppl 1):S187–S204.
  • Lucas M., Mirzaei F., Pan A., Okereke O., Willett W., O’Reilly E.J., Koenen K., Ascherio A. Coffee, Caffeine, and Risk of Depression among Women. Arch. Intern. Med. 2011;171:1571–1578. doi: 10.1001/archinternmed.2011.393.
  • Kawachi I, Willett WC, Colditz GA. A prospective study of coffee drinking and suicide in women. Arch intern Med. 1996;156:521–5.
  • Skrovankova S., Sumczynski D., Mlcek J., Jurikova T., Sochor J. (2015). Bioactive compounds and antioxidant activity in different types of berries. Int. J. Mol. Sci. 16, 24673–24706. 10.3390/ijms161024673
  •  Jeong HS, Hong SJ, Lee TB, Kwon JW, Jeong JT, Joo HJ, Park JH, Ahn CM, Yu CW, Lim DS. Effects of black raspberry on lipid profiles and vascular endothelial function in patients with metabolic syndrome. Phytother Res 2014;28:1492–8.
  • Edirisinghe I., Banaszewski K., Cappozzo J., et al. Strawberry anthocyanin and its association with postprandial inflammation and insulin. British journal of nutrition. 2011;106(6):913–922. doi: 10.1017/s0007114511001176.
  • Crozier S. J., Preston A. G., Hurst J. W., et al. Cacao seeds are a “super fruit”: a comparative analysis of various fruit powders and products. Chemistry Central Journal. 2011;5:p. 5.
  • Grassi D., Desideri G., Necozione S., Lippi C., Casale R., Properzi G. Blood Pressure Is Reduced and Insulin Sensitivity Increased in Glucose-Intolerant, Hypertensive Subjects after 15 Days of Consuming High-Polyphenol Dark Chocolate. J. Nutr. 2008;138:1671–1676. doi: 10.1093/jn/138.9.1671.