How To Self Test For Food Sensitives or Bio-Individuality

By Dr Ernst
April 13, 2020

Have you ever noticed that your blood sugars elevate or your ketones drop drastically, all of a sudden, as if for no good reason? It’s possible that you had a reaction to a particular food you ate – even healthy food! Bio-individuality is a new buzz word in the functional health care space. It’s the idea that each person has unique nutritional needs and can react to foods differently.

If you’re following the cellular healing diet and staying “in ketosis” each week (Ketones over 1.0, GKI less than 6) you may not have to worry about trigger foods. But if you find you’re struggling to get into ketosis or you’re getting kicked out of ketosis easily you need to consider testing after ingesting your meals to determine if you’re eating a food that you are sensitive to.


One simple way to determine if you are reacting to a specific food (i.e. uncovering a food sensitivity) is to test your ketones/sugars before and after you eat that food in question. Note: it’s best to do this when isolating one specific food group rather than an entire meal with multiple ingredients. This three three-step self-test is certainly worth doing because once you know what foods are getting in your way, you can eliminate them from your diet and then your results can improve drastically.

Most common foods of sensitivity: Coffee, Eggs, Corn, Dairy, Legumes, Sugar Alcohol Substitute Sweeteners (Xylitol, Erythritol, etc), Wine/Alcohol, higher-carb vegetables (sweet potatoes, carrots, etc), citrus fruits (grapefruit, lemons/ limes) and even “healthy” pre-packaged foods.


  • Test before eating, 60 min after eating and again 3 hrs after eating
  • Avoid foods that increase blood glucose by more than 30mg/dl
  • Avoid foods that decrease ketones by more than 0.5 mm/dl


To discover trigger foods that may kick you out of ketosis, you conduct three ketone and three glucose tests in one day. The purpose of these tests is to see if the food you eat the day of the tests adversely affects your ketone and glucose levels and thus blunts your ability to reach an optimal Glucose Ketone Index (GKI) – blood sugars less than 99 and ketones greater than 1.0.

Step Number 1: Your Pre-Eating Baseline for Ketones & Glucose

The purpose of this first test is to get your pre-prandial (before eating) or baseline ketone and glucose readings. You need this so you can compare it to the results you get after you eat the food in question. The best time to conduct this test is when you are fully fasted—before breakfast or at least three hours after any previous food consumption. After testing, note your results.

Step Number 2: The Post-Easting Test – Reaction/Sensitivity to Food Group

The purpose of this second test is to introduce food to your diet and discover your ketone and glucose levels 60 minutes later. It is best to eat only the food in question (the more ingredients mixed with it, the more variables in the equation). We suggest eating the recommended or typical portion size for that food. After testing, note your results, then reference below for understanding the results.

Step Number 3: The Post-Eating Test #2 – Determining Your Recovery Time

Take this test at the three-hour mark after eating the food in question. This is the test that allows you to see how quickly your ketones and glucose recover (or don’t recover) after you eat the food. After testing, note your results.

Understanding the Results

If your blood sugars elevated more than 30 mg/dl, or your ketones reduced more than 0.5mmol/L between the Pre-Eating baseline and Post-Eating (60min) test, it’s a positive test for food sensitivity – you should avoid eating that food item altogether.

If, however, with the same food group in question that caused the spike in sugars/drops in ketones, your Post-Eating (3 hr) test returned to the pre-eating baseline – your body was able to recover properly from the food group in question within the allowable time which suggests that while sensitive, you could have the food group in question – but should limit the number of times you eat that food group within a week to only once or twice per week to limit the negative effects it has on your results.

Note: some foods may cause an increase in ketone levels or a drop in blood sugars due to their high-fat content like MCT (medium-chain triglyceride) oil, heavy cream, coconut cream, and coconut oil; this is OK and further proof as to why you should incorporate these food groups into your diet.

Share on twitter
Share on pinterest
Share on facebook