Bariatric Surgery: Why It's About More Than Just Nutrients

When it comes to bariatric surgery, many people — even some healthcare professionals — still think it’s just about eating less and taking a multivitamin. But the truth runs much deeper.

Obesity, from a medical perspective, is a multifactorial disease.
It can be driven by:

• Medication side effects

• Hormonal disruption

• Environmental influences (like learned eating habits from family)

• Cognitive and neurobehavioral factors (such as dopamine-seeking behaviors)

• Immune dysfunctions (like vitamin and mineral deficiencies)

• Genetics and epigenetic factors

Sometimes it’s just one cause; often, it's a combination.
The main point?
Obesity is complex, and healing must address the whole picture — not just food intake.

A Food-First, Whole-Body Approach

As a Registered Clinical Nutritionist, I take a holistic approach to supporting bariatric clients.
I believe wholeheartedly in the principles of Hippocrates and Edison:

"Let food be thy medicine and medicine be thy food."
"The doctor of the future will give no medication but will interest their patients in the care of the human frame, diet, and the cause and prevention of disease."

This philosophy means starting with:

• A whole-foods-based diet

• Restoring gut health

• Removing inflammatory agents

• Exploring diagnostic testing

• Targeted supplementation

• Lifestyle changes to support sustainable health

Different Surgeries, Different Needs

Understanding what type of bariatric surgery a person has undergone is critical.
Procedures like sleeve gastrectomy, gastric bypass, and duodenal switch all cause structural and functional changes in the digestive tract — meaning nutrient absorption is altered differently for each.

When parts of the digestive tract like the stomach, duodenum, or jejunum are removed or reduced, there's less surface area available to absorb nutrients.
While the body can adapt over time, support is essential to avoid major deficiencies.

Supplementation, food choices, and symptom management must be highly individualised — considering factors like whether the client prefers capsules, powders, or liquids, and how their daily lifestyle looks post-surgery.

Key Symptoms to Watch For After Surgery

Some of the major symptoms I track include:

• Hair Shedding:
  Surgery is a significant stressor. The body focuses energy on vital processes like breathing and digestion, often diverting resources away from "non-essential" functions like hair growth.
  This shedding is temporary but can be distressing — targeted nutrient support can help.

• Dumping Syndrome:
  Dumping syndrome can occur either immediately or later after eating. It’s often triggered by meals high in sugar, simple carbs, or fat. Symptoms can include nausea, dizziness, diarrhea, or a rapid heartbeat.
  Managing dumping syndrome involves adjusting what is eaten, how much, the frequency, and balancing macronutrients carefully.
  We also assess for insulin resistance, which can compound symptoms.

Bariatric Surgery and Mental Health

Can bariatric surgery impact mental health? Absolutely.

Patients undergoing bariatric surgery have been found to have higher rates of depression compared to non-surgical obese patients of similar age and BMI.

There are several reasons for this:

• Nutrient deficiencies affecting brain chemistry

• Stress and trauma from the surgery itself

• Ongoing inflammation, both pre-existing and new

These factors can reduce neurotransmitter production, increasing the risk for anxiety, depression, and mood swings.

Supporting mental health post-op means focusing heavily on:

• Gut healing

• Nutrient sufficiency (especially B vitamins, zinc, magnesium, omega-3s)

• Stable blood sugar

• Anti-inflammatory lifestyle support

Why Gut Health, Protein, and Calorie Sufficiency Matter

Let’s start with protein and calories:

• Proteins are literally the building blocks of your body — needed for tissue repair, immune function, hair growth, hormone production, and so much more.

• Calories provide essential energy.
  Without enough calories to meet your Basal Metabolic Rate (BMR), your body can't maintain basic functions, let alone heal.

Unfortunately, post-op clients often fall well below their calorie and protein needs — leading to fatigue, slow wound healing, hair loss, brain fog, and even muscle wasting.

That’s why I often recommend 5 smaller, balanced meals a day post-surgery.
For example:

• Breakfast: A smoothie packed with calories, protein, and nutrients

• Mid-morning snack: The rest of the smoothie or a protein bite

• Lunch: A half-portion meal

• Afternoon snack: Second half of lunch or a nutrient-dense snack

• Dinner: A small but complete meal

• Optional evening snack: Something light but nourishing if needed

The idea is to spread nutrition throughout the day to meet your needs without overwhelming your new, smaller stomach.

How Bariatric Surgery Affects Nutrient Absorption

Nutrient absorption happens primarily in the stomach, duodenum, and jejunum — the parts often bypassed or reduced during surgery.

Because of this:

• Vitamins and minerals are at high risk of deficiency.

• Micronutrient repletion is essential — often for life.

• The body must rely on other sections of the intestine to pick up the slack — but only if abundant nutrients are available.

This is why standard multivitamins are often not enough. Post-op care must involve targeted, practitioner-grade supplementation.

Essential Nutrient Support After Surgery

Here’s what I often prioritise:

• Probiotics containing Lactobacillus, Bifidobacterium, and/or Saccharomyces boulardii to support gut wall integrity.

• Antimicrobial herbs to rebalance the gut flora after surgery stress.

  Surgery can disrupt the gut microbiome — like shaking a house and hoping all the furniture lands back in place.

• Blood Sugar Stabilisers like inositol and fish oil to support insulin sensitivity.

• Sleep Support supplements such as magnesium, L-theanine, or 5-HTP to improve recovery.

• Anti-Inflammatory Support through curcumin, fish oil, and anti-inflammatory foods to reduce systemic inflammation.

The Risk of SIBO After Bariatric Surgery

There’s a significant 47% increased risk of Small Intestinal Bacterial Overgrowth (SIBO) after bariatric surgery.

Signs of SIBO include:

• Bloating that worsens through the day

• Gas and discomfort after meals

• Constipation or diarrhea

Managing SIBO post-surgery involves antimicrobial strategies, probiotics, and sometimes specific dietary interventions to reduce bacterial overgrowth and restore balance.

Testing to Support Post-Op Health

Testing helps individualise care even further:

• Blood Testing:
  Monitoring vitamin and mineral levels with your GP is critical.

• Organic Acids Test (OAT):
  This at-home urine test provides a comprehensive snapshot of metabolic function, gut bacteria, yeast overgrowth, nutrient deficiencies, mitochondrial health, and more.

Testing ensures that we’re not just guessing — we’re tracking real data to guide recovery.

In Summary: Post-Bariatric Priorities

• Focus on gut healing

• Ensure nutrient sufficiency

• Meet calorie and protein targets

• Optimise sleep hygiene

• Support emotional and mental health

• Reduce inflammation

• Monitor and personalise supplementation

Final Word

Bariatric surgery is just the beginning.
True healing happens afterward — through consistent, compassionate, and personalised care.
Addressing gut health, emotional health, nutrient sufficiency, and lifestyle factors can mean the difference between short-term weight loss and true long-term wellbeing.

Because you deserve more than just "eat less and take a pill."
You deserve to thrive.