The connection between under-eating and digestive function may not be obvious or spoken about much in the mainstream — but it's important to consider!
Not only does undereating leave the body lacking the macronutrients, vitamins, minerals, and phytonutrients it needs to function, it can impact how our digestive processes function and even lead to certain digestive issues as a result!
In this article, we're going to explore a few ways that undereating can negatively impact our digestive health:
We Need Adequate Nutrients to Create Digestive Secretions
We need specific nutrients, and enough of them, in order to create digestive secretions like stomach acid, digestive enzymes, and bile.
Stomach acid is important for helping us to digest proteins, protect us against pathogens, in the absorption of B12, and more. In order for our stomach acid to work for us however, we need nutrients like zinc, iodine, and B vitamins like vitamin B1. We need to ensure we're getting enough of these nutrients through our nutrition, so our body can produce enough stomach acid.
Digestive enzymes (both salivary amylase found in saliva, and pancreatic enzymes secreted by the pancreas), are compounds that break down the nutrients we ingest, into their usable parts. For example, the enzyme lipase specifically "digests fats," meaning it breaks down fats that we ingest in our food, into fatty acids that can be then used by the body.
We need to be consuming enough protein through our nutrition, in order to be able to make these in the body.
Bile is a substance that is created in the liver, and stored, concentrated, and released by the gallbladder. Bile is what helps us to emulsify fats, enables us to absorb fat-soluble vitamins like vitamins A, D, E and K, and helps us to rid of waste products like bilirubin and excess cholesterol.
In order to make bile, we need enough dietary cholesterol, amino acids, and vitamins.
All of these digestive secretions ensure that our digestive processes are running smoothly. It's important to make sure we're consuming the nutrients required to allow the body to make these for us!
Undereating Can Impact the Health and Resilience of Your Gut Microbiome
Though it may not seem obvious to us, our gut bugs need food to survive, too.
Undereating can mean that the microorganisms in our gut microbiome don't have access to the food (like fiber), that they need to survive and thrive. Starving our gut bugs can result in lowered populations of beneficial bacteria like lactobacillus, bifidobacterium, bacteroides fragilis, faecalibacterium prausnitzii, and more.
These commensal flora provide us with many benefits as their host, as long as they're well fed! They play roles in intestinal barrier integrity, neuroimmunity, microbial balance, protect us against pathogens, produce healing short-chain fatty acids, promote anti-inflammatory processes, and more.
We need a diverse, rich microbiome to support our digestion, immunity, hormones, metabolic health, and more. Undereating can compromise the health of our microbiome, therefore potentially compromising these other systems and processes.
Undereating Can Impact the Health of Your Intestinal Lining
Certain microbes, like in the case of faecalibacterium prausnitzii, play an important role with regard to the health and integrity of our intestinal lining.
This species creates healing byproducts called short-chain fatty acids (SCFA's), as a result of fermenting fiber that we consume. It also helps to promote anti-inflammatory processes, as well as support a healthy mucosal lining.
One of these SCFA's is butyrate. Butyrate is an energy source for the cells that line our intestines, and helps to keep our intestinal lining healthy and in integrity, helps to keep inflammation at bay, and more.
Undereating Can Contribute to Gastroparesis
Gastroparesis is a term to describe slowed or impaired gastric emptying, where food doesn't move past the stomach into the upper part of the small intestine efficiently enough.
This is problematic, because it can contribute to a downstream of digestive issues, and is associated with uncomfortable digestive symptoms.
Some of these common signs and symptoms are:
bloating and distention
indigestion
belching
feeling "full" after a few bites of food (premature satiety)
abdominal pain
nausea, vomiting
When we aren't consuming enough nutrients and calories, muscles throughout our digestive system may not have the nutrients required to function optimally and can begin to atrophy.
This can lead to gastroparesis, which can impact motility (how effectively food moves through our system, how we have bowel movements), it can impact the microbiome, and contribute to uncomfortable symptoms.
Undereating Can Contribute to Constipation
We need enough "substance" to form healthy bowel movements.
If we aren't consuming enough substance, enough fiber, through our food to create well-formed, bulked stool we may see constipation develop as a result.
Likewise, undereating can mean that your thyroid isn't accessing the nutrients it needs to function optimally. An underactive thyroid can also contribute to constipation, as it slows down metabolic and digestive processes.
Eating enough, both to have enough sustenance, and to ensure we're giving our body access to the nutrients it needs to function optimally, is important for overall health and wellbeing, but also specifically our gut!
If you're struggling with an eating disorder and need immediate help, you can reach out to the NEDIC helpline at 1-866-633-4220 in Canada and NEDA at 1-800-931-2237 in the US.
If you want to look deeper into whether gluten sensitivity could be contributing to your symptoms (once you've ruled out celiac), and would like some guidance on how you can support your gut in healing, I'd definitely recommend checking out my Gut Rehab Intensive where we work 1:1 to support your gut health.