Thiamine, or vitamin B1, is a vital nutrient that supports glucose metabolism and helps cells use stored energy. It is essential for maintaining a healthy heart, central nervous system, and immune function.
This article explores the vitamin’s potential in assisting weight loss and explains what happens when we don’t have enough of this vitamin.

How Does Thiamine Affect Weight?
Scientists haven’t discovered a direct link between thiamine and weight. However, as the vitamin’s primary role is to support energy metabolism, inadequate vitamin levels can disrupt metabolic processes, hormones, and other mechanisms that regulate weight.
Note: Learn how other B vitamins and weight loss are related.
Can Lack of Thiamine Cause Weight Loss?
There is inconclusive evidence about the effects of vitamin B1 deficiency on weight loss. In one human study, researchers induced thiamine deficiency to examine the resulting symptoms and health disorders. Weight loss was one of these symptoms.
Other symptoms of vitamin B1 deficiency included fatigue, sleep disorders, cognitive decline, and abdominal problems. These results suggest a more severe thiamine deficiency can lead to serious health disorders, including heart, nerve, and muscle abnormalities.
study, researchers observed a thiamine deficiency in obese and type 2 diabetic patients who had recently lost weight or reduced their food intake. These results suggest weight loss increases the risk of B1 deficiency, and not the other way around.
A study on sheep demonstrated no significant effect of thiamine intake on weight, but it potentially enhanced fat breakdown.
Does Thiamine Boost Your Metabolism?
Thiamine plays a crucial role in glucose, lipid, and amino acid metabolism. Optimal vitamin B1 levels enable a smooth conversion of food into energy that cells use to perform their functions. Low thiamine levels can hinder these processes, slowing down metabolism.
Causes of Thiamine Deficiency
Clinical thiamine deficiency is rare in developed countries because many foods are fortified with B vitamins. However, it may occur due to the following reasons:
- Excess alcohol intake – Decreases food intake and interferes with vitamin B1 absorption.
- Poor diet – A diet high in white flour, sugar, and fats decreases thiamine absorption, while increased food processing (cooking, frying) destroys the vitamin.
- Certain medical conditions – Diabetes, AIDS, liver disorders, an overactive thyroid gland, anorexia, and other health problems often cause malnutrition or decreased thiamine absorption, leading to its deficiency.
- Bariatric surgery – Post-surgery stress increases the demand for vitamin B1, but the reduced stomach size and side effects such as nausea and vomiting may decrease its intake.
- Pregnancy and breastfeeding – Nausea and vomiting in pregnancy and increased nutritional needs in pregnant and lactating women often result in nutrient deficiencies.
- Aging – Studies suggest older adults are at an increased risk of thiamine deficiency due to naturally low thiamine absorption, regular use of medications, and chronic diseases.
- Strenuous physical activity – Athletes often experience a heightened need for thiamine and other vitamins from the B complex due to increased energy expenditure and nutrient loss through increased sweating.
Note: Many athletes embrace the numerous benefits of IV therapy for athletic performance. Find out how it works!
Symptoms of B1 Deficiency
Early symptoms of vitamin B1 deficiency include the following:
- Fatigue
- Agitation
- Abdominal discomfort
- Nausea
- Vomiting
- Disturbed sleep
- Weight loss
Untreated thiamine deficiency may lead to more severe symptoms, such as the following:
- Prickling and burning sensation in the arms and feet
- Muscle atrophy
- Partial eye paralysis
- Memory loss
- Confusion
- Chest pain
- Tachycardia
- Pulmonary edema
How to Treat Thiamine Deficiency
Thiamine deficiency symptoms can be reversed with vitamin supplements, IV therapy, or both. Doctors usually recommend multivitamins with a B complex because other B vitamin deficiencies usually accompany a lack of vitamin B1.
Patients with more severe symptoms can benefit from a faster treatment – a vitamin B injection or vitamin B IV therapy. IV therapy involves the intravenous delivery of B vitamins for quick nutrient recovery.
A balanced diet is an essential cofactor in the treatment of thiamine deficiency. Patients should avoid processed foods, simple sugars, and alcohol and eat thiamine-rich foods, including the following:
- Fortified bread, cereals, pasta
- Whole grains
- Pork
- Chicken
- Fish
- Yogurt
- Legumes
- Brown rice
Conclusion
Thiamine is vital for energy metabolism. Adequate vitamin B1 levels contribute to our overall well-being and may improve the body’s ability to regulate weight.
All nutrient deficiencies impede health, potentially leading to weight gain, hormonal imbalances, insulin resistance, and other health problems. The best way to ensure the smooth functioning of our body is to enjoy a nutrient-rich diet, engage in regular, moderate physical activity, and take vitamin supplements if needed.


