When people think of “fat burning nutrients,” they often turn to green tea or caffeine. But neither of those will be beneficial if you don’t get enough of the baseline nutrients that allow your metabolism to function properly. You can guzzle coffee all day long, but if your body doesn’t have the building blocks necessary to produce enzymes and other machinery for efficient fat burning, you’ll just end up jittery and frazzled with no reduction in body fat.
This article will review four key nutrients necessary for fat burning and explain how they improve metabolic function. Putting them together with a personalized nutrition, training, and lifestyle program will allow you to start experiencing positive changes in body composition.
First, let’s review how fat loss works:
Remember that for fat loss, it’s always necessary to achieve an energy deficit in which you take in fewer calories than you expend. This is best achieved by eating in a way that allows for the following:
You control hunger and avoid food cravings
You feel energized and active
You’re able to exercise at a high intensity and recovery efficiently
For most people, the biggest obstacle to achieving this reality is that their blood sugar is poorly regulated and cells are resistant to insulin. In this metabolic environment, fat burning will be sluggish and energy levels low. No one wants to exercise or be active when they feel tired, so inactivity becomes a natural state, which is the opposite of what needs to happen if you want to lose body fat.
Why is blood sugar regulation so important?
When you eat a meal, carbohydrates are digested into the blood stream as glucose (sugar), providing energy for cells throughout the body. Insulin is released from the pancreas to facilitate the use of glucose for energy. In an ideal world, your cells are very responsive to insulin and blood sugar is tightly controlled.
However, due to lack of physical activity, too many calories, and a diet high in unhealthy carbs, your body’s ability to control blood sugar can become dysregulated so that you experience large peaks and valleys in glucose. Poor glucose management is associated with hunger, food cravings, and fatigue.
In a healthy body, blood sugar is tightly regulated, with the pancreas releasing just enough insulin to store glucose, while maintaining blood sugar in the ideal range. However, in response to blood sugar spikes, the pancreas will overestimate the amount of insulin needed, releasing too much. Any time insulin is elevated, an enzyme called hormone sensitive lipase (HSL), which mobilizes fat stores so that you can use them for energy, will be blocked. At the same time, lipoprotein lipase (LPL), which stores fat, will be elevated.
Another thing that happens when too much insulin is present is that the receptors on your cells become less sensitive, meaning that even more insulin is needed to regulate the same amount blood sugar. In this environment, insulin levels are high and fat storage increases, whereas the ability to burn fat shuts down. Because energy isn’t getting into cells as it should you’ll be more likely to feel fatigue and have poor exercise tolerance.
To solve this situation, diet and exercise are your first line of defense but it’s also necessary to ensure you aren’t chronically low in essential fat burning nutrients:
Known as the nutrient of insulin sensitivity, magnesium plays an important role in energy metabolism and fat burning in the body. Any time insulin is elevated in the blood, fat burning is practically non-existent. For the body to start using fat for fuel, insulin must go down, and the hormone glucagon must go up.
Additionally, magnesium impacts how energetic you feel due to its role in ATP production. You’ll remember that ATP is the unit of energy that is produced by the mitochondria. Magnesium is involved in the conversion from ADP into the usable energy source, ATP.
Studies consistently link insulin resistance to low magnesium levels. For example, a study from Newfoundland found that subjects with the highest dietary magnesium intake had the lowest levels of insulin and vice versa. Magnesium intake was also inversely associated with body fat, with individuals who consumed more magnesium being leaner.
Supplementation can also assist with fat loss in overweight subjects who have low magnesium levels. A randomized trial of obese kidney patients with low magnesium found that supplementing with 365 mg of magnesium for 3 months resulted in a decrease in waist circumference compared to a placebo, which coincided with improved insulin sensitivity and A1C levels (a marker of long-term blood sugar regulation). The number of subjects presenting with obesity and metabolic syndrome also decreased.
Take Away: Don’t let a magnesium deficiency keep you from reaching your goals. Supplementing with 10 mg per kg of body weight (650 mg for a 65 kg individual) will improve magnesium status and support a lean body composition, while preventing diabetes.
For the body to burn fat for energy, the fat molecules must be transported into the mitochondria of the cell. An amino acid composite found in animal products, carnitine is responsible for this, getting fats into cells so that they can be used for energy in the body.
Carnitine also has an insulin sensitizing effect. For example, one study of individuals with elevated glucose showed taking 2 grams of carnitine a day for 6 months improved insulin sensitivity and lowered blood pressure. A second study found that taking carnitine while on a short-term lower calorie diet improved glucose tolerance and insulin sensitivity compared to a placebo group.
How does it work?
By elevating carnitine levels, fat burning increases and you give the cell the right genetic machinery to raise metabolic rate. You’ll have more energy and be more active, raising the number of calories you burn through spontaneous physical activity during the day. For example, in a study of elderly centenarians, supplementing with 2 grams of carnitine resulted in significantly less physical and mental fatigue and they lost 1.8 kg of body fat. Subjects also experienced an increase in muscle mass.
Carnitine is available in all animal products, though beef provides the greatest amount (60 mg in a 4 oz. steak), whereas fish, chicken, dairy, and other animal products contain less than 8 mg per serving. Therefore, vegetarians and people who don’t eat meat at most meals will benefit from taking a carnitine supplement. A dose of 2 to 4 grams of carnitine has been shown to improve body composition and increase exercise performance during intense training.
Additionally, anyone who is not digesting their food well will not be able to break down and absorb the carnitine from the meat they are eating. Not only is carnitine supplementation a good bet but digestive enzymes may improve digestion and absorption of carnitine and other necessary nutrients.
Take Away: Carnitine improves energy use and fat burning, reducing mental and physical fatigue. Supplementation is most important for people who don’t frequently eat meat or have digestive issues and are not absorbing nutrients well.
#3: Fish Oil
Fish oil is an interesting fat burning nutrient, impacting insulin sensitivity and metabolic rate. Fish oil provides the omega-3 fats EPA and DHA, which are important because they will improve the sensitivity of every cell in your body to insulin.
Cells are made up of a lipid bilayer—basically, a double layer of fat. The type of fat you eat dictates which fats make up this layer, impacting the health of the cell. Cells that have a greater incorporation of omega-3 fat in them are more sensitive to insulin.
Fish oil also impacts metabolic rate by enhancing something known as uncoupling protein genes. Simply, the uncoupling proteins lead to excess calories being burned by raising body temperature. One study found that overweight men who ate about 3 grams of omega-3 fat a day increased metabolic rate by a whopping 51 percent. They burned an extra 920 calories during the period after eating when metabolism was elevated, and they experienced an increase in the use of fat for energy.
Another study showed that combining 3.3 grams fish oil supplementation with interval training and a Mediterranean diet for 12 weeks resulted in 2.6 kg of fat loss and 5 percent decrease in abdominal fat. Insulin and inflammatory markers also decreased by about 35 percent. This study highlights how fish oil is one part of the equation for improving body composition and you’re going to get the best outcome if you combine nutrition and training that elicits the adaptations you want (in this case fat loss).
In addition to fatty fish like salmon and sardines, fish oil can be gotten from grass-fed animal products (the omega-3s are in grass, which the animals eat and incorporate into their cells) or supplemented. When supplementing, up to 3 grams a day is recommended, depending on your metabolic state (people with insulin resistance, diabetes, and obesity may need more), how much you are getting from diet, and your intake of omega-6 fats, which come in nuts, seeds, and cooking oils (omega-6 and omega-3 fats need to be balanced).
Take Away: Ensuring you get enough fish oil in your diet will optimize insulin sensitivity and raise energy expenditure—a combination that encourages fat burning and makes it more likely you will achieve an energy deficit.
#4: Vitamin B12
Along with all of the B vitamins, B12 plays an important role in fat burning and low levels are associated with increased body fat. Best known as a nutrient that prevents anemia, vitamin B12 is necessary for proper red blood cell formation, which carries oxygen to working muscles, powers exercise, and keeps you energized throughout the day. It is also involved in growth and development processes in the body and plays an important role in cognition and brain health.
A series of studies show that low levels of vitamin B12 are linked to higher body fat levels in humans. One British study found that pregnant women with lower B12 had more body fat and a greater degree of insulin resistance. For every 1 percent increase in body mass, there was a 0.6 percent decrease in circulating B12. Other markers of body fat metabolism were also independently associated with B12.
A second study from Turkey found that out of 976 subjects, those with the lowest vitamin B12 levels had significantly greater risk of obesity. Vitamin B12 level was lower in patients with metabolic syndrome and insulin resistance as well, though the findings did not reach statistical significance.
Animal studies support the association between impaired metabolism, poor ability to burn fat, and increased body fat. For example, a study of pregnant female rodents showed that when dietary B12 was severely restricted in the diet, they experienced impaired fat metabolism and increased inflammation. Most of their offspring died within 24 hours of birth. Researchers theorize the deleterious effects from lack of B12 were due to increased oxidative and corticosteroid stress that overwhelmed the antioxidant defense system.
The thing about vitamin B12 is that it needs to be balanced with the other B vitamins, all of which are involved in some way in metabolism. For example, thiamine (vitamin B1) and biotin (vitamin B7) act as a cofactor for enzymatic reactions that enable fat to enter the Krebs cycle to be burned for energy. Vitamin B3 (niacin) is involved in the production of molecules involved in fat burning, such as carnitine. Vitamin B5 (pantothenic acid) is involved in the production of ketone bodies (a byproduct of fat burning that the body can use for energy).
Although it’s entirely possible to get all the B vitamins from the food you eat, many people are not doing so due to the following reasons:
Poor quality diet: The Western diet of ultra-refined processed foods is deficient in B vitamins, which is why many foods are fortified with these nutrients. However, one expert explains that when deficiency of B vitamins is long term, as in the case of the high-carb western diet, fortification with synthetic vitamins may not help because the enzymatic pathways in the body that allow for fat burning and other processes to occur are damaged or atrophied.
Vegan or vegetarian: Vitamin B12 is only present in animal foods: Meat, fish, poultry, eggs, and dairy products. Supplementation can solve this, just make sure you are getting B12 in the form of methylcobalamin, which is the type that naturally occurs in the body. Many supplements use cyanocobalamin, which is not bioavailable.
High intake of BCAAs, either from diet or supplementation: The BCAAs are a blend of amino acids that are involved in protein synthesis and often supplemented in athletes. A high intake can deplete B vitamins because they are necessary for the production of enzymes involved in BCAA metabolism.
Digestive problems: If your GI tract is not working like clockwork, or you have inflammation in the intestines, the body won’t absorb your Bs. As you age, absorption decreases making it more likely you will be deficient in B vitamins. In this case, supplementation won’t help. Rather you need to focus on healing the gut: Removing foods that stimulate a poor digestive response and supplementing with digestive enzymes and hydrochloric acid is your first line of defense. Increasing probiotics and fibrous vegetables is also recommended.
Medication use: Medication is well known for depleting nutrients. Birth control reduces levels of B3, B9, and B12, and anti-depressants, antibiotics, and glucose lowering drugs all decrease absorption of B12.
When supplementing, opt for a B complex that supplies all the Bs you need in the right ratios and choose a methylated form, which increases absorption and bioavailability.
Take Away: Along with all of the B vitamins, B12 plays an important role in fat burning and low levels are associated with increased body fat. Supplementing with a methylated B complex will provide the body with the nutrients it needs for optimal fat metabolism and leanness.