How Nutrient Deficiency Causes Weight Loss Resistance in Women

Updated: October 26th, 2025

• Weight loss is more complex than simply eating less and moving more.
• What you eat can matter as much as – or even more than – how much you eat.
• It’s hard to get all the nutrients you need from the food you eat – even when you are eating well.
• Lack of specific nutrients can impact weight loss resistance in a range of ways.
• Specific strategies to address nutrient deficiencies can help kick start weight loss.

“I exercise every day. I don’t snack between meals. I’ve been paying attention to portion sizes for months. My doctor told me if I ate less and moved more, I’d lose weight – so why haven’t I lost a single pound?” Carrie asked on a recent consultation call.

I’ve heard some version of this statement so many times from women who have been told that losing weight was a simple matter of eating less and exercising more. But like anything that’s been simplified too much, for many women that just doesn’t work. I always tell these women, like I told Carrie, that simply counting calories isn’t the answer. In fact, some of the most obese people in our society are those who eat the least. How can that be?

To really understand this phenomenon, it’s crucial to have a good understanding of nutrition. Good nutrition goes far beyond having enough to eat; quality of food is far more important than quantity. But in our culture, it’s easy to get large amounts of poor quality food very inexpensively – hence the “super size me” attitudes of many consumers. The overabundance of cheap, processed foods means that many Americans are overfed but undernourished. The food they are putting into their bodies just doesn’t provide the essential nutrients they need to flourish.

Why do so many people have nutrient deficiencies?

Many Americans have one – or multiple – nutrient deficiencies that might be contributing to their weight loss resistance. Approximately 1/3 of Americans don’t get enough magnesium, vitamin C, vitamin E or Vitamin A in their diets, and more than two-thirds are low in Vitamin D. Even more startling, 9 out of 10 Americans have a deficiency of Omega-3 essential fatty acids. Why are so many people in our culture falling short in the nutrition department?

A large part of the problem is our modern diet, which is vastly different from that of our ancestors. Ultraprocessed food, high in simple carbohydrates and sugar, dominates the supermarket shelves. This food is less expensive than organically grown fruits and vegetables, grass fed meats, and wild caught fish – but often has no real nutritional value. This kind of food may fill you up temporarily, but it certainly won’t keep your body in good health – and it will sabotage your weight loss goals!

And then there’s the myth that fat is the enemy. Too many women have bought into this, avoiding all fats entirely. Or, they are consuming the wrong kind of fats by using vegetable oils rather than the healthier options that provide your body with the Omega 3s it needs.

Finally, even the food that does give you the nutrients you need is less powerful than it used to be. Industrial farming practices have stripped the soil of many nutrients, which means fruits and vegetables provide far less nutrition than they did even a few decades ago. Even if you love vegetables, it’s tough to eat enough of them to get the nutrients your body needs.

How does a lack of nutrients impact weight loss?

You probably know that if you aren’t getting the nutrients your body needs, you won’t feel great. But do you know just how these deficiencies can impact your weight?

All nutrients have an important job in your body – and when they can’t perform their functions properly, many things happen to your system that make weight loss more difficult. Let’s take a look at five specific ways that nutrient deficiencies can cause weight loss resistance:

1. Disruption of quality sleep

Poor sleep quality can affect weight in many ways. Research has shown that poor sleep impacts hormones that signal both hunger and fullness, as well as the ability to resist specific cravings. Most important, however, is the research indicating that sleep deprivation affects your metabolism. A University of Chicago study showed that the body’s ability to process insulin dropped by more than 30% within four days of insufficient sleep. And when your body can’t respond appropriately to insulin, fats in your bloodstream will be stored rather than processed.

2. Inefficient metabolism

People often simplify metabolism, describing it as either fast or slow, but this term actually describes how your body processes and uses the food you eat. If your metabolism is functioning properly, weight loss will be easier. It’s when you have a dysfunctional metabolism that your body may hang on to more calories than it burns – and that can impact your ability to lose weight. If your basal metabolism – the calories you need just to stay alive – is reduced, it can impact both the amount of calories you expend when active and the calories spent simply processing your food. Therefore, it could be harder for you to lose weight than someone of a similar weight with a properly functioning metabolism.

3. Increased fatigue and exhaustion

It’s true that the more you move, the more calories you expend. But if you are so tired that you have a hard time getting out of bed, you certainly won’t have the energy to exercise. And if you’re feeling exhausted, you are far more likely to opt for takeout instead of preparing yourself a healthy meal.

4. Problems with gut health

Your gut can suffer greatly when you lack the proper nutrients in your body. If your gut is perpetually inflamed due to poor diet, or you have digestive issues such as leaky gut syndrome, absorption of the nutrients becomes a problem. This means that toxins permeate the protective lining in your gut and circulate throughout your body, causing systemic inflammation. This could mean your brain isn’t getting the right messages – including the messages that you are full, or that fat should be burned for energy. Remember, serotonin is produced in the gut.

5. Imbalanced hormones

Hormones carry messages to your brain. When hormone levels are not optimal, these messages get skewed. Your major hormones – adrenaline, cortisol and insulin – have a big impact on your ability to lose weight. If levels of these hormones are too high or too low, you could find yourself developing weight loss resistance.

Specific nutrients that impact weight loss resistance

Now that you know how nutrient deficiencies can cause weight loss resistance, let’s take a quick look at some of the specific nutrients you need to maintain a healthy weight.

Magnesium

The mineral magnesium, found naturally in leafy green vegetables, whole grains, nuts and beans is involved in over 300 chemical reactions throughout your body. Magnesium helps promote restful sleep and good digestion, improve insulin and blood glucose levels, and regulate metabolism.

B Vitamins

The entire group of B vitamins can help increase energy and promote weight loss. These vitamins help metabolize protein, carbohydrates and fats as well as assisting with central nervous system activities. Vitamin B1 helps convert carbohydrates into glucose and boost energy. Food sources include wheat, green leafy vegetables and meats. Vitamins B2, B3 and B6 all impact production of thyroid hormone. A healthy thyroid is essential to maintaining a healthy weight. B2 is found in organ meats, milk, eggs, and almonds. B 3 can be found in fish, meat, milk, and fruits like mangoes and tomatoes. Good sources of B6 include chicken, cabbage, sardines, brown rice and eggs. Finally, B12 can help you lose weight by boosting metabolism. Good sources of B12 include salmon, beef, chicken, and oysters.

Vitamin A

Vitamin A can help keep your gut healthy and helps your body fight infections. There are two forms available to your body – retinol and beta-carotene. Beta-carotene is converted to Vitamin A in your body. You can get retinol by consuming animal products such as whole milk, cheese, liver and oily fish. Beta-carotene is found in dark green vegetables such as spinach, as well as yellow, red, and orange fruits like carrots, tomatoes and sweet potatoes.

Vitamin C

Many people think of oranges and other citrus fruits when they think of vitamin C, but plenty of vegetables and fruits are high in this vitamin and are essential in boosting our immune system. Research has shown that low levels of vitamin C have a direct link to larger waists, and higher Body Mass Index (BMI) and blood fat levels. These findings are connected to the relationship between vitamin C and L-carnitine, which carries energy to all the cells in your body, ensuring a healthy metabolism. Because Vitamin C is important to the production of carnitine, if you don’t have enough your energy levels will dip and prompt your body to store fat in your muscles.

Vitamin D

Research has indicated that vitamin D can actively assist your body in losing weight by restricting calories. If you are deficient, then, this biological weight loss path can be blocked. And to make matters worse, there is also evidence that being overweight could cause a vitamin D deficiency. Vitamin D deficiency can also play a large part in healthy sleep. The best natural source of vitamin D is sun exposure. Very few foods naturally contain vitamin D; the best sources are fatty fish such as salmon, tuna and mackerel. Many foods in the American diet are fortified with vitamin D.

Vitamin E

Vitamin E and vitamin K work together to produce red blood cells and improve muscle functioning. Lean muscle mass burns more calories than body fat, and can make your metabolism more efficient in burning calories. Kiwifruit, safflower oil, wheat germ, spinach, broccoli and sunflower seeds are all good sources of vitamin E.

Omega 3s

Omega 3 fatty acids have been studied intensely and have been shown to be essential for burning fat. These essential fatty acids lower insulin levels, increase metabolic rate, lower cortisol levels, improve the fat burning ability of your liver, and improve blood flow to your muscles during exercise. Because your body cannot produce Omega 3s, you have to get them from food or supplements. Some of the best sources are wild caught fish, including Atlantic mackerel, Alaskan salmon, and albacore tuna; walnuts, chia seeds, and flaxseeds.

Strategies to Heal – and Prevent – Nutrient Deficiencies That Lead to Weight Loss Resistance

Weight loss can feel like a losing battle sometimes, especially if you don’t understand how all aspects of your life impact your efforts. Now that you understand how important it is to be sure your body isn’t lacking any vital nutrients, here are some strategies to help ensure that nutritional deficits aren’t inhibiting your weight loss goals.

Eat like our ancestors did

Avoid processed foods as much as possible. When you can, choose wild game – or at the very least, organic, grass fed meats. Eat organic fruits and vegetables whenever possible. Try to get your healthy fats from plant sources like extra-virgin olive oil, coconut oil, nuts and seeds. Eliminate sugar and refined carbohydrates from your regular diet. Eat protein at every meal to stabilize blood sugar.

Prioritize good quality sleep

Sleep is when your body repairs itself and detoxifies, so if you aren’t allowing enough time for adequate sleep, you’re robbing your body of the ability to heal. Set up your bedroom to promote healthy sleep; keep it cool, dark, and electronics-free.

Reduce stress, spend time outside, and exercise

Making time to take a walk, bike ride, or simply sit in the sun for several minutes early in the day can boost your vitamin D levels. And if your time outdoors doubles as your exercise time, you may also boost energy and reduce stress without needing to squeeze in one more thing. Exercise also promotes healthy sleep, digestion, and balanced hormones and blood sugar. Find something you love to do that gets you moving, and do it every day. Chronic stress can seriously diminish nutrients as your body fights for survival. It doesn’t matter what your de-stressing activities look like, as long as you’re doing them daily.

Boost your gut health

This goes hand in hand with eating well. Whole, unprocessed foods are rich in all the things you need – vitamins, minerals, antioxidants, essential fatty acids, fiber and anti-inflammatory compounds. If your gut health is particularly poor, you may need to add nutrients like zinc and glutamine that help mend the lining of your digestive tract. Digestive enzymes can help with nutrient absorption, and a probiotic can help replenish the good bacteria your gut needs for optimal functioning.

Dig deep with a functional medical practitioner

Resistance to losing weight is often one of many indicators that something more is going on with your health. Conventional practitioners often won’t really dig into the root cause of weight loss resistance. Take the time – and any necessary tests – to determine what’s really going on in your body.

Fight weight loss resistance by feeding your body well

It may be more difficult to eat well and get the nutrients we need than it was for our great-grandparents, but it’s certainly not impossible. All it takes is a little information and dedication to feeding your body – and soul – the right things every single day. When you let go of bad habits and focus on getting all the nutrients you require, you just might find that your body lets go too – of that extra weight it’s been holding on to!