Ask the RD | October

Our registered dietitian, Jamie, offers answers to nutrition-related questions our community have submitted over the past month.

The information shared within this blog is meant for informational purposes only and should not be received as medical advice.

If you have a question to submit, please click the button and watch for a response the following month. Before submitting a question, we invite you to visit the main page for Ask the RD and enter a keyword into the search box — your question may already be answered!

• What are the signs/symptoms your body may have difficulty processing a certain food? 

  Food intolerances and sensitives typically involve the digestive system having a hard time processing some foods, which results in a repeated reaction to a specific food. Many people with food intolerances or sensitivities have gastrointestinal symptoms ranging anywhere from heartburn, upset stomach, abdominal pain or cramping, nausea and vomiting, to bloating, gas, or diarrhea. Non-gastrointestinal symptoms may include headache, sinus congestion, or skin and joint irritation. Some common food intolerances include: 

  • Lactose intolerance: Occurs when the body doesn’t make enough lactase, the enzyme that aids in the breakdown of lactose (milk sugar) in the gut.  

  • Gluten intolerance: Occurs when the body has a hard time breaking down gluten, a protein found in wheat, rye, and barley.  

  • FODMAP intolerance: Occurs when the body has difficulty digesting specific carbohydrate foods. 

  • Additive intolerance: Can occur when the body is sensitive to certain food additives such as preservatives, emulsifiers, artificial sweeteners, and other agents.  

  It may be tricky to figure out which specific food or ingredient your body is reacting to. Keeping a food diary may be helpful in identifying patterns of food intolerances and the culprit foods that have triggered them. When keeping a food diary, record not only the type of food consumed and the time of which it was consumed, but also your emotional state. Due to the strong brain-gut connection, emotional stressors can have a strong influence on digestive tolerance. 

  Share your food diary and symptoms with your primary care provider for help in determining next steps.

  Previous related Ask the RD posts:    

  • What advice do you have for maintaining a healthy diet when navigating food allergies. (September 2025)

• What are the benefits of fermented foods and does variety matter?

  Fermented foods often contain probiotics and support a healthy digestive tract. Probiotics are live microorganisms that benefit the gut microbiome by fostering the growth of good gut microbes while creating a less favorable environment for the bad microbes.

  In addition to promoting microbial homeostasis, probiotics from fermented foods also help to increase microbial diversity, improve digestion, and decrease inflammation throughout the body. A greater variety of fermented foods in the diet results in a greater variety of good microorganisms in the gut.

  For optimal gut health, aim to include at least one, if not more, servings of fermented foods each day such as yogurt, cottage cheese, kefir, sauerkraut, kimchi, kombucha, miso, and fermented vinegars. 

• Are there nutritional benefits from caffeine?

  Moderate caffeine consumption of 200-400 mg per day (the amount found in 3-5 cups of coffee) can provide some health benefits. Examples include:

  • increased mental alertness and focus,

  • improved mood,

  • and decreased risk for certain diseases such as Type 2 diabetes, heart disease, Alzheimer’s, and Parkinson’s. 

  Also keep in mind that caffeinated foods and beverages often include other nutritional components that may not be beneficial for your health.

  • The added sugar and fat in your chocolate bar, flavored syrup and whole milk in your morning latte, added sugar or artificial sweetener in your sodas, or additives like taurine in your energy drinks can all negatively impact your health.

  • It can cause feelings of anxiety, jitters, sleep disturbances, and digestive issues including acid reflux and/or laxation of the bowels.

  Regular caffeine consumption can certainly be part of a healthy diet, as long as you tolerate it and can manage or control the not-so-healthy components that may come along with it. 

• Does the temperature matter when drinking water?

  Differences in water temperature have little, if any, impact on overall absorption and hydration. Some minor differences include:  

  • Cold water may be a better choice when exercising, doing physical labor, or spending time in a hot environment as it may aid in cooling your internal body temperature and in preventing dehydration. Cold water may also act to keep you more alert and focused when experiencing low energy levels.  

  • Room temperature to slightly warm water can aid in digestion and may feel more thirst quenching. 

  • Warm or hot water may be beneficial to ease nasal congestion or sore throat and may help increase internal body temperatures during times of cold.  

  As many people have a hard time staying hydrated, drinking enough water is more important than the temperature itself. Ultimately, it comes down to personal preference, so choose whichever water temperature you enjoy and tolerate. 

• Are tests available to measure healthy gut bacteria?

  When considering the health of your microbiota, the best place to start is by looking at your dietary patterns, as well as your bowel habits. To support optimal microbial balance, follow a healthy diet consisting of mostly whole/minimally processed foods, a variety of fiber-rich and fermented foods, and adequate hydration while limiting processed foods, simple sugars, and saturated fats.  

  Monitor your GI symptoms and bowel habits, paying attention to any bloating, cramping, abdominal pain, plus the frequency, color, and consistency of your stools. Healthy bowel habits vary from person to person but can include passing a bowel movement every other day to three times per day; color can range from light tan to dark brown. Optimal consistency is a smooth, soft, snake-like log as opposed to hard lumpy pellets or mushy to liquid stools. Discuss any concerns such as significant abdominal pain, bloody or black stools, pale clay-colored stools, or frequent constipation or diarrhea with your primary care physician or gastroenterologist.   

  A gastroenterologist can order stool studies to check for specific microorganisms or inflammatory markers in the GI tract. They can also use blood tests or breath tests to assess certain conditions. At-home microbiome tests include sending a small stool sample to a lab for analysis to determine types, diversity, and ratios of bacteria living in your colon. However, these tests can be costly and are not considered clinically diagnostic as there is still a lot to be learned about the microbiota and validated treatment options. 

  Learn more about healthy and not-so-healthy poop here.

Jamie Libera, RD, LD, CCTD, is a clinical dietitian within the Providence health system. She works closely with the heart programs in offering consultations for heart failure patients, cardiac rehab patients, and serves as the nutrition consultant for Basecamp Prevention + Wellness. Jamie offers monthly nutrition-based classes and a monthly heart-healthy recipe as part of Basecamp’s free community programming.