Select Page

Case Study: The Effects of Diet on Heart Rate Variability

by | Jul 21, 2016 | application, case study, health

There are countless diets and nutrition plans being touted as “the solution” but with such varied results. Why will some people thrive on a nutrition plan when others gain weight or get sick?

The body’s response to different stressors like unknown inflammatory triggers, food sensitivities, or nutritional deficiencies is very individual and therefore the nutritional plan needs to be personalized for best results.

The body’s response to different stressors like unknown inflammatory triggers, food sensitivities, or nutritional deficiencies is very individual and therefore the nutritional plan needs to be personalized for best results.

Depending on a person’s current health condition (especially gut health), activity level, and genetic predisposition to food allergies/sensitivities, the same diet can cause drastically different results for different people. An individual can even have different responses to a nutritional plan at different times in their life as their stress levels, hormones, activity level, and health vary.

This is where an objective, individualized measure of the body’s response to lifestyle factors such as Heart Rate Variability comes in. HRV can measure the Autonomic Nervous System (ANS) activity and balance. The ANS is tied closely to processes in the body such as digestion and inflammation. This means that HRV can actually help a person detect when a diet is eliciting a negative physiological response prior to symptoms arising so he/she can remove the stressor and adjust their diet accordingly for the best success.

HRV can actually help a person detect when a diet is eliciting a negative physiological response prior to symptoms arising so he/she can remove the stressor and adjust their diet accordingly for the best success.

I will cover a couple examples of when Heart Rate Variability proved to be a very useful tool in monitoring and adjusting diet changes and discuss some important considerations when using HRV to monitor nutritional progress.

Active 32-Year-Old Male [CASE STUDY 1]

We treated a very active, 32-year-old male who was struggling with some fat mass he had accumulated.  He was well-built with an athletic past and had a very good knowledge of fitness and nutrition. We began monitoring his Heart Rate Variability along with his exercise and nutrition to see if we could pinpoint any unknown stressors.

We initially thought that the patient’s work and family life were causing stress and that he was overdoing it with his exercise and nutritional plans. But before we made any adjustments to his exercise and nutrition, we wanted to get a better idea of what a typical few weeks were like in his life. For three weeks, we had him thoroughly track his diet and exercise sessions and take a short HRV measurement every morning.

During those three weeks, I noticed that the patient would have a significant drop off in HRV scores every 7 to 10 days. The other days were shown to have very little daily fluctuation and were generally higher.  When we met again, I asked him what was different on those low HRV days compared to his normal-metric days since there was no real correlation with the HRV drop to his work, family, lifestyle and exercise. The patient proceeded to tell me that he was participating in an experimental nutritional protocol in which he would limit his carbohydrate intake to an extreme for 7 to 10 days, depending on what the program advised, then he would binge on carbohydrates for 1 to 2 days.

When we met again, I asked him what was different on those low HRV days compared to his normal-metric days since there was no real correlation with the HRV drop to his work, family, lifestyle and exercise.

This type of diet is essentially a ketogenic diet (very low carbohydrate diet intended to force the body to utilize its fat fuel source over the carbohydrate fuel source) with built in carbohydrate reloading/refueling periods.  We found that the larger the carbohydrate intake on the carbohydrate cycling days, the larger the HRV crash. He was also actually gaining weight and having an increased number of days when he experienced illness. This could have been due to the type and/or quantity of foods he was ingesting on the high carbohydrate reload days.

While this carbohydrate cycling protocol has proven successful for some people in losing weight or changing body composition, HRV and subjective data showed that it obviously did not work well for our patient.

We promptly educated our patient on the impact the carbohydrate cycling protocol was currently having on his health, and proceeded to implement a nutrition plan based on his family history, blood work, and supplemental data from his previous attempts at dieting. The result was that his fat loss progress accelerated and his HRV values increased and stabilized.

26-Year-Old Female Athlete with Pain  [CASE STUDY 2]

Another example where HRV monitoring helped us detect nutritional triggers was a case of a 26-year-old, high-level volleyball player who came to us with many long-standing issues including pain.  Since her pain levels were fluctuating in an inconsistent pattern, we put her on an HRV monitoring plan so that her entire care team could see if there were correlations between her HRV scores and lifestyle factors.

Over the next few months of working closely with her and tailoring her nutrition and exercise plans, we saw a substantial increase in her HRV scores. There was also significantly less setback in her progress and an increase in her function and mood.

However, during one period when she was away from the clinic, I noticed a series of HRV scores that were her lowest since we started monitoring and I received an email from her stating that her symptoms had started to return and she was having some issues with her exercise sessions. When I called her, she told me she had started a liquid food cleanse consisting of only juices, soups, and water.

We had previously made sure her nutrition was supporting her increased activity and health status but her friend suggested she go on this cleanse diet since she claimed it made her feel really good.  However, it was clear from her significant decrease in HRV and the return of her symptoms that the diet was not providing enough macro-nutrient and caloric support for her lifestyle and activity level.

It was clear from her significant decrease in HRV and the return of her symptoms that the diet was not providing enough macro-nutrient and caloric support for her lifestyle and activity level.

We immediately had her stop the cleanse diet and return to her regular nutrition plan.  The next day, she came down with a cold that knocked her out for a week and caused setbacks in her treatment plan.

Once she was able to make it back into the clinic, we explained to her the importance of what information our team gives her and encouraged her to utilize her HRV as a guide when making diet and lifestyle changes in the future. She got back on the plan we had initially set for her as a team and continued to see progress with a continuous increase in her HRV scores over time.

General Note on HRV Monitoring

HRV is a great tool if you are looking to optimize your health and ensure that you are giving your body the needed resources to thrive.  But since Heart Rate Variability is multi-factorial, changing your nutritional habits should be done without any other drastic change to your lifestyle.

For example, if you start going to a CrossFit class for the first time while drastically changing your diet, it will be difficult to determine the main cause of changes in your HRV trend. Is it the large increase in frequency and intensity of exercise, or, is your diet introducing inflammatory triggers or not meeting or significantly exceeding the demands your body?

If you are going to use HRV to monitor the systemic impact of your diet, it needs to be the most significant change you make during that time period in order for you to be able to understand the diet’s effects. I’m not saying that diet changes cannot be implemented at the same time as other lifestyle changes, but, for most people who are using HRV to monitor progress, it can be very confusing to determine the cause of changes in your HRV when you have made multiple, simultaneous adjustments in your lifestyle, such as diet and exercise.

If you are going to use HRV to monitor the systemic impact of your diet, it needs to be the most significant change you make during that time period in order for you to be able to understand the diet’s effects.

Final Note

Some nutrition protocols can elicit an initial decline in HRV. For example, for certain detoxes and short-term diet plans such as those targeting parasites, candida overgrowth, or SIBO (small intestinal bacterial overgrowth), a temporary decline in HRV is expected during the die-off period or when the toxins are mobilizing and releasing from the body.

Under proper guidance, and as long as HRV returns to normal or better levels, this is an acceptable part of an intentional plan. If HRV unexpectedly changes, especially drastically, this is usually a sign that there is an issue present. Having the guidance of an experienced clinician or health coach can be a huge asset in interpreting your data and situation.

Interested in learning more about the science behind HRV and how monitoring it can help improve your health and performance? Get access to the “Foundations of Heart Rate Variability” course in August!

Want to receive information about upcoming courses or posts about HRV application and case studies? Then, sign up for our newsletter.

2017 enrollment is currently closed

The Foundations of Heart Rate Variability Course will open again later this year.

Feedback from participants has been so positive, that we will continue offering periodic short enrollment periods to keep the quality of the experience as high as possible. Since enrollment will be limited, we will be announcing first to those who have registered interest here.

Thank you! You will be the first to know when the course enrollment opens.

2017 enrollment is currently closed

 

The Foundations of Heart Rate Variability Course will open again later this year.

Feedback from participants has been so positive, that we will continue offering periodic short enrollment periods to keep the quality of the experience as high as possible. Since enrollment will be limited, we will be announcing first to those who have registered interest here.

Thank you! You will be one of the first to be notified when the course next opens enrollment.

2017 enrollment is currently closed

 

The Foundations of Heart Rate Variability Course will open again later this year.

Feedback from participants has been so positive, that we will continue offering periodic short enrollment periods to keep the quality of the experience as high as possible. Since enrollment will be limited, we will be announcing first to those who have registered interest here.

Thank you! You will be one of the first to be notified when the course next opens enrollment.