The low FODMAP diet is a medical diet designed to help reduce gut symptoms. So what do you do if you switch to the low FODMAP diet and start feeling tired or getting headaches? Sometimes these symptoms can be related to a change in diet and other times are caused by other factors. The questions below can help you determine if switching to the low FODMAP diet is a factor for you.
Have you removed sources of caffeine from your diet?
Like coffee, energy drinks, Coca-Cola/Pepsi lots of black tea. Significantly reducing or eliminating caffeine from your diet can cause short-term withdrawal symptoms like headaches, fatigue, dizziness and mood swings while your body adjusts. Remember that the low FODMAP diet doesn’t need to be coffee or tea free. Read our guides about low FODMAP coffee or low FODMAP tea to learn more.
Have you reduced the amount of food you are eating?
Unfortunately, many newbies to the low FODMAP diet remove foods entirely from their diet instead of swapping them. Deleting foods from your diet can reduce the calories (energy) available for your body and your nutrient intake, which can make you feel tired or headachy. The fix for this mistake is to swap the high FODMAP food for a low FODMAP food from the same category. For example, regular bread for wheat sourdough bread OR cow’s milk for lactose free cow’s milk or soy milk made from soy protein.
If you need help making low FODMAP swaps, then check out our FODMAP Made Easy membership – we have downloadable handouts, online courses and email support to make the process easy.
Are you drinking enough fluid?
Dehydration is a common cause of headaches. It’s easy to drink less fluid if you usually consume a lot of high FODMAP drinks like juice, fizzy drinks with high FODMAP sweeteners, smoothies with high FODMAP fruits, certain teas or coffee with cow’s milk. Think about how many glasses of fluid you were drinking before starting the low FODMAP diet and make sure you match that. If you aren’t a big fan of plain water, try cranberry juice, low FODMAP smoothies, low FODMAP tea or coffee.
Have any of your medications or supplements changed?
Changes to medications or supplements can cause side effects like tiredness and headaches. If these symptoms persist, please talk to your healthcare team.
It’s good to note that Monash University, the lead researcher of the low FODMAP diet, don’t recommend starting any new supplements like probiotics during the first phase of the diet as these can cloud results (1).
Has your daily routine changed?
Our bodies love routine. So it can take a while for your body to adjust to changes in sleep patterns, exercise, or work/social schedules.
Tiredness and/or headaches can also be caused by other illnesses, hormonal changes (females, this point is for you), food chemical sensitivities, anxiety and stress, as well as other lifestyle factors. If these symptoms persist, then please talk to your healthcare team.
Switching to the low FODMAP diet might cause headaches and tiredness if you have reduced your calorie intake, cut out caffeine-containing foods, or limited your fluid intake. Removing FODMAPs themselves has not been shown to cause “withdrawal” type symptoms, so make sure you talk to your healthcare team if symptoms persist.
- Varney, J. Prebiotics and probiotics – should I include them on the low FODMAP diet? Monash FODMAP. 2016. Sourced from: https://monashfodmap.com/blog/prebiotics-and-probiotics-what-are-they/