Since DNA and microbiome testing are costly and slow, here are three diet exercises that you can start now!
1. Keep A Food Diary for Your Diet
Written:
Write down everything you eat and pay attention to your body’s reaction over the next 48 hours. Record any reaction: tingling mouth, upset stomach, gas, diarrhea, or cramps. Guess what? You are now on the road to mindful eating! You can dictate notes in your smartphone, or jot things down on an old-fashioned note pad. There are also many specialty food and fitness diaries you can use to add a personalized kick (amazon, thefooddiary).
An online search for food diaries brings up option like the Cleveland Clinic’s sample and the Dairy Council of California. The NIH and CDC even offer free templates for food diaries too! If you’d rather type out your food choices, a spreadsheet is another simple way to organize entries by date, time, what you ate, how much you ate, and how you felt. You can add columns for medications, exercise, blood sugar, blood pressure readings, and anything else you want to track.

Using an App:
There are many apps for the purpose of tracking your food (1). Digital tracking of food and calories (as well as activities like exercise, sleep, and meditation) can make it easier to keep a diary consistently. My Fitness Pal is famously easy to use app that can help keep track of the foods you positively and negatively react to. I have several friends who have lost significant amounts of weight using MFP, although I found their calorie estimation sometimes difficult if I wasn’t eating brand name foods. For more sophisticated apps, check out MyFoodDiary: a staff-curated food diary service that claims to avoid the errors of missing or duplicated data. Of course, your options don’t end there; the Apple App Store is full of food tracking apps (like MyNetDiary), and Google Android offers dozens of food planning and tracking apps too.
The Point Is…
Whether you write it down or use an app, the point of a food diary is to establish a baseline for future food experiments and make you more aware of what you eat. To make the most use of your food diary, write down everything you eat as seen as you eat it. That includes beverages, that piece of hard candy from the reception desk, or the bag of chips you couldn’t resist buying at the 7-11. Be specific and precise with the type of food and portion size. For more reading and tips, check out eatingwell, livescience, and kaiserpermanente.
If you are already tracking other data like medication timing, blood sugar, or blood pressure, a diary can make it easier to find correlations. Eat those salty chips or drink that high-potassium coconut water and then measure your blood pressure. A week or so of food diary records may already show you some habits and patterns that you’d like to change. Did you not realize you had an ice cream bar every night before bed? No breakfast and starving at lunch? Big dinner with wine and coffee and feel overloaded and can’t sleep after? Skin breaks out after eating tomatoes? All of this will help you begin to understand which dietary choices are right and wrong for you.
2. Try An Elimination Diet
Beloved by traditional nutritionists and functional medicine practitioners alike, elimination diets are the old-fashioned gold standard for diet and nutrition experiments. Like the name implies, an elimination diet focuses on what you don’t eat. In its purest form, you would fast everything for 24 hours and then reintroduce food items one day at a time. This practice allows you to observing your reactions to specific foods. However, it’s important to check in with your doctor before trying this, as fasting may have different effects for different people. If this seems daunting, you can start by eliminating your most suspected food (FODMAP or protein) without changing the rest of your diet and observing what happens.

What Should I Eliminate?
Although different people react to different things, obvious targets for elimination include: fructose, gluten, nightshades, soy, dairy, nuts, eggs, chocolate, and all known family or personal allergens, etc. (2). Do you feel better or worse? Do you crave the eliminated food? How’s your GI responding? If the suspicious food is something you’ve been eating daily, skip it for a week or two and note what happens. Usually, it takes around two weeks for your microbiome to shift in response to changes to diet, so this process may take awhile. Here are some other suggestions from Dr. Axe and webmd.

After your elimination fast period, begin re-introducing suspect foods. Observe your reactions, both immediately (ex. mouth tingling) and 12-24 hours later (ex. skin rash). It’s easiest to observe GI reactions (tingly tongue, gas, constipation or diarrhea, etc.), but other reactions may be detectable through elimination and reintroduction. Your food diary or app can be a big help here—use it to keep track of what you reintroduce and how you responded.
Things to Be Careful Of In an Elimination Diet
Before starting an elimination diet, it’s important to check with your physician in case severely restricting calories may cause problems. Also, if you have a history of anaphylaxis, you need to strictly avoid known trigger foods. If you don’t know what food triggered the episode, it is best to only do reintroduction of foods under medical supervision and with an EpiPen handy. If you are already underweight, an elimination diet may cause further unwanted weight loss. Elimination diets may prevent you from getting enough micronutrients, so unless a particular supplement is on your suspicious list, keep up any supplementation you are already taking (3).
3. Give Intermittent Fasting (IF) A Go
Fasting is the hot new diet (or more accurately, eating pattern) fad. A quick Bing search on “Intermittent Fasting” brings up more than two million results! In IF, it’s not about what you eat, but when you eat it. Our ancestors had to survive through periods of little or no food when crops failed, when hunting was scarce, or when seasonal foods were not available. As such, it’s been argued that IF, like the paleo diet, is similar to our ancestral evolutionary diets (4).
Goals may include weight control, CNS reset, improved glucose tolerance and the reduction of risk factors for diseases like obesity, diabetes, and dementia. IF increases Human Growth Hormone (HGH), lowers insulin levels, and increases insulin sensitivity. It also kick-starts cellular repair, and may trigger positive changes in gene expression (4). Weight loss is by far the most popular reason to try IF; for the obvious reason that it significantly reduces total daily or weekly calorie intake; and for the less-obvious reasons that it increases metabolism.

How Should I Fast?
It’s fairly easy to fast 12-16 hours a day by eating supper early (or skipping it altogether and making lunch your big meal) and fasting from afternoon to a late breakfast the following morning. The 16/8 method restricts eating to an 8-hour window; you could skip breakfast or dinner, depending on your sleep schedule. If you’re up for it and your schedule permits it, you can also try water fasting or severely limiting calories for 1-2 days a week. While the toxicity hypothesis is disputed, “cleanses” serve a similar purpose, to push your body into ketosis (a state of fat burning rather than sugar burning) for a period of time to reduce fat stores and give your insulin and immune systems a rest.
Concluding Thoughts:
These are three simple, if not necessarily easy, experiments you can try at home to find the diet best for you! They can work in concert with any DNA and microbiome results, further educating yourself and getting you closer to your unique, optimal diet.
Written by: Ellen M. Martin, Becca Malizia, BS, Bonnie Feldman, DDS, MBA
Resources
- Learn more about your dietary tools, techniques and testing companies here
- Discover your uniqueness in our first Food Matters post here
- Read about pre- and probiotics, antibiotics and food here
References
- “The 21 Best Apps For Food Journaling.” Redbookmag. https://www.redbookmag.com/body/healthy-eating/advice/g614/lose-weight-apps-tools/?slide=8 . Accessed 30 July 2018.
- Walsh, Brian. “Food sensitivities and intolerances: How and why to do an elimination diet.” Precision Nutrition. https://www.precisionnutrition.com/elimination-diet . Accessed 30 July 2018.
- “What’s an Elimination Diet.” WebMD. https://www.webmd.com/allergies/allergies-elimination-diet . Accessed 30 July 2018.
- “Intermittent Fasting 101- The Ultimate Beginner’s Guide.” healthline. https://www.healthline.com/nutrition/intermittent-fasting-guide#section1 . Accessed 30 July 2018.