When your stress hormones rise and stay chronically high, your metabolism changes from glucose oxidation to fatty acid oxidation.
Glucose oxidation, in which your cells burn sugar and oxygen for energy, is your default metabolism to provide you with energy. When your liver runs out of sugar/glucose reserves, your metabolism changes to fatty acid oxidation. In short, your cells start to burn fat and oxygen to provide you with energy.
Once your glucose stores are restored, you go back again to your default metabolism of glucose oxidation. Fatty acid oxidation is your back-up, and is activated through a stress state—lack of glucose, as well as high levels of adrenaline, cortisol, prolactin and/or estrogen.
Metabolism, PTSD & Weight Gain
Fasting, exercise, keto, vegan, and low carb diets all promote fatty acid oxidation. What these methods also do is raise your adrenaline and cortisol in response to a lack of glucose.
With short fasts, diets, and normal regular exercise, you will generally go back to glucose oxidation as your default metabolism.
However, when you are under chronic stress, as you are most likely in when you are experiencing Complex Trauma or PTSD, your metabolism starts to become conditioned to a fatty acid oxidation metabolic state.
Stress, Lactic Acid & Fatty Acid Oxidation
Keep in mind that this is a backup system that is activated through stress. It is a secondary metabolic system meant to deal with shortage short-term, with a focus on survival. This entails conserving energy as much as possible, a mechanism in which energy/food is not converted to glucose but is converted to… wait for it... fat.
What this means is that even if you eat a “healthy” diet or eat very little, your continuous stress state converts any food you eat into fat; your system has been set to generate energy through fatty acid oxidation because you are in survival mode, and your body acts accordingly.
Furthermore, fatty acid oxidation creates lactic acid as a byproduct, which further reduces the amount of oxygen that is available to your cells, thus impairing energy production.
Impaired Metabolism & Carbon Dioxide
Cold hands and feet, lack of energy, low thyroid, and low body temperature are all signs and symptoms of low metabolic rate, fatty acid oxidation, and a chronic stress state.
Glucose oxidation creates carbon dioxide as a byproduct. Carbon dioxide helps to push oxygen into the cells, which leads to a greater oxygen saturation of your body cells.
You can test this by taking a deep breath in, holding it for 3-4 seconds, breathing out, holding for 3-4 seconds, and repeating the process. At first it will be difficult because you are in a stress state of low oxygen/high lactic acid, but as you increase the level of carbon dioxide in your blood by holding your breath for a few seconds, you increase cell oxygen saturation.
As you do this exercise for a few cycles, you will likely feel slightly light headed, then start to feel better, and your thoughts quiet down a bit. This is the effect of better cell oxygen saturation due to increased carbon dioxide.
Glucose Oxidation vs Fatty Oxidation
Increasing your carbon dioxide will also help steer you towards glucose oxidation versus fatty oxidation as this process decreases your lactic acid levels.
(As an aside, this exercise comes straight out of The Course on Sleep & Insomnia Related to Post-Traumatic Stress.)
What else can you do to reduce weight and improve your metabolism?
Of course, you will need to address the emotional part of what keeps your stress hormones high and what makes you burn through any glucose stores far too quickly.
The resources available on this website are a good place to start.
Sufficient Food Intake To Curb Stress
In terms of diet, you will need to eat a nutrition replete diet.
Remember that fasting, low carb, vegan, and keto diets promote fatty acid oxidation as does excessive exercise, so you want to avoid these when you are dealing with Post-Traumatic Stress. Aging, unfortunately, also promotes fatty oxidation as iron, iodine, estrogen, and PUFA accumulate in the body.
In terms of food, you will have to eat sufficient amounts to promote glucose oxidation. At first, this will be tough because you will likely gain more weight before your body becomes aware you are not in a chronic stress state anymore and starts to switch back to glucose oxidation opposed to fatty acid oxidation.
You might also have developed some intolerance to certain foods, which often is due to chronically heightened stress hormones, excess lactic acid, and impaired metabolism. You will have to experiment, and keep experimenting, with which foods you can tolerate and provide you with a lot of nutrients.
Weight Gain, PTSD & Further Suggestions
Sufficient nutrients, proper sleep, and processing of emotional stress due to Post-Traumatic Stress can help to regulate your stress hormones. You might also want to look into supplementing with metabolism enhancers; T3, aspirin, progesterone, and caffeine all enhance metabolic rate. You do need to eat sufficiently if you take these as you need something to burn; otherwise you will just raise your stress hormone levels again.
I know food has become a religion for many. The above are my suggestions based on my own research and experiments and specifically how diet relates to Complex Trauma & PTSD. I trust you will do your own research and come to your own conclusions.
Here are some more resources you could further explore: