Low carb diets are trendy but they are no FAD. More and more research is showing health benefits of low carbohydrate diets for weight loss, fat loss, diabetes, cardiovascular disease, and brain and nerve function.
What are the Health Benefits of Low Carb Diets?
The USDA guidelines recommend that 45-65% of your calories come from carbohydrates. To put it into perspective, if you’re a woman in your 30’s who exercises lightly 1-3 times a week, you roughly need 1,600 calories a day to maintain your weight. Based on the USDA recommendations, you would need about 180-260 grams of carbohydrates a day.
However, research is mounting against eating that many carbs (sadly, because who doesn’t love a piece of good freshly baked bread!).
For more than a decade, a study after another is showing that if you want to lose weight and fat tissue, improve your diabetes and cholesterol numbers, improve cognitive function, and even potentially increase longevity and prevent cognitive diseases associated with aging, you have to eat way less carbs.
Here are some proven health benefits to eating a low carb (carbohydrate) diet.
Low Carb Diets Boost Weight and Fat Loss
One study compared a low carb diet (40 grams of carbohydrates or less a day) to a general healthy eating diet. After 3 months, participants lost more weight in the low carb group, 15 lbs, compared to only 5 lbs in the general healthy eating group.
Another study that compared a low carb diet (30 grams of carbohydrates or less a day) to a low fat diet (30% of calories or less to come with fats AND eating 500 calories less a day). Despite eating more calories, people on the low carb diet lost more weight (13 lbs vs 4 lbs) and were more successful at reducing their triglyceride level (more on that below). The low carb diet was also better at improving insulin sensitivity (more on that below as well).
Low Carb Diets Help you Lose Belly Fat
Another study found that in both men and women, a low carb diet (10% of calories from carbs and 63% of calories from fat) was better for weight loss, overall fat loss, AND fat loss in the abdomen area compared to a low fat diet (60% of calories from carbs and 22% of calories from fat).
An interesting side note of the study is that the men who participated lost more weight and fat on the low carb diet even though they ate 300 calories more on average every day. Also, then men in the study didn’t see as much of a dip in their resting energy expenditure (metabolism, or the amount of calories the body burns just for internal organs to function) on the low carb diet. This is important because resting energy expenditure usually drops with weight loss. In other words, the low carb diet didn’t crush their metabolism as much the low fat diet did.
If you’re a woman reading this, don’t be discouraged. It doesn’t mean you won’t have these benefit too. The difference between the diets didn’t reach statistical significance (a whole lot of math involved) in the women who participated, but that doesn’t mean there won’t be a significant difference for YOU.
Low Carb Diets Improve Type 2 Diabetes
One of the studies that I just mentioned above showed that 30 grams carbohydrates or less improved insulin sensitivity.
Insulin is the hormone that forces glucose to enter your cells. You want to have enough insulin AND you want your cells to sense it so that glucose doesn’t linger in the blood. When your cells stop seeing insulin, or in other words become less sensitive to insulin, more and more insulin needs to be pumped into your bloodstream.
But more insulin production isn’t the solution because sensitivity to insulin is the problem. Overtime, your blood glucose will remain high because the cells can’t use insulin and your blood sugar level reaches the pre-diabetes range. If you don’t change the way you eat, your blood sugar will eventually reach the diabetes range.
Pay a close attention to high-normal glucose. Fasting blood sugar level is considered normal if less than 99 mg/dL by conventional medicine standards. However, fasting blood sugar level above between 80 mg/dL and 99 mg/dL indicates that you may have an insulin sensitivity issue.
When low carb diets improve insulin sensitivity, that means insulin is more functional. Glucose level will be kept in the optimal range, and your body won’t need to produce too much insulin.
And if you’re trying to lose weight, it’s important for insulin to remain low because high levels prevent fat loss.
Another diabetes number you want to pay attention to is HgA1C, the 3-month measure of blood sugar. One study that looked at people with type 2 diabetes found that after 4 months, a low carb diet (20 g carbs or less) reduced HgA1C from 7.3 to 6.2. The majority of participants either discontinued or reduced their diabetes medications. They also they lost weight and reduced their triglyceride level.
When compared to a low glycemic index diet (eating foods that don’t raise blood sugar sharply) combined with cutting 500 calories a day, a low carb diet (less than 20 g) lead to more reduction in HgA1C (dropped 1.5 points vs. only 0.5 point). In addition, people lost more weight on the low carb diet (24 lbs vs. 15 lbs) and a higher percentage of them reduced or eliminated their diabetes medications. The study was done over 6 months.
Many other studies support the benefits of low carb diets for people with diabetes. Since most people don’t enjoy cutting calories or food, you can switch where the calories are coming from and reduce carbs to see improvement in your health.
Start by calculating how many carbs you need. If you need help putting it all together, see how you can schedule a private consultation.
Low Carb Diets Reduce Inflammation and Improve Cardiovascular Disease Risk Factors
I have mentioned triglycerides several times before, so what are they really?
Triglycerides are simply the fat in your blood. When you eat more than you need, any excess calories become triglycerides and are then stored in your fat tissue. High triglyceride level, above 150 mg/dL, is a risk factor for heart disease and heart incidents.
You might think that since triglycerids are fats, then eating a low a fat diet would help reduce their level. But that’s not the case.
Low carb diets reduce triglycerides level better than other diets. In fact, eating too many carbohydrates, more than 55% of calories, raises triglycerides level (study).
Another study found that compared to a conventional diet, a low carb diet (20 grams initially then more added gradually) was better at reducing triglycerides by 28% after 1 year (compared to 1% only). It was also better at increasing HDL-cholesterol, the good cholesterol, by 18% compared to 3% on the conventional diet. This improvement in HDL-choelesterol level was also seen in anther study that compared the low glycemic index/cutting 500 calories to 20 grams carbs or less. In the low carb group, HDL-cholesterol increased by 5.6 points while there was no change in the other group.
And a meta analysis that pooled results from several studies found similar results. Low carbohydrate diets ranged between 20-40 grams carbohydrates or 4-40% of calories or less. Looking at all of them together, low carb diets reduced total cholesterol, LDL-cholesterol (bad cholesterol), and triglycerides while they increased HDL-cholesterol (good cholesterol).
Other markers of inflammation and cardiovascular disease risk factors improve with low carb diets. A study that compared a low carb diet (less than 40 grams a day) to a low fat diet (less than 30% calories) showed that after 12 months, people on the low carb diet improved inflammatory markers as well as endothelial (arteries) function. They also lost more weight (12 lbs vs. 3 lbs) and more fat tissue.
Low Carb Diets Improve Brain Function
High carbohydrate diets can contribute to the mechanism of development of Alzheimer’s Disease. That’s because excess insulin production accelerates the damage in nerve cells in the brain.
Animal studies and uncontrolled clinical trials show that a low carb diet can reduce the progression of Alzheimer’s disease, Parkinson’s disease, traumatic brain injuries, and strokes. In these conditions, nerve cells die and lose function. It’s hypothesized that ketone bodies, the organic compounds the body switches to burning for energy instead of glucose on a low carb diet, protect against nerve damage.
Do Not Eat a Low Carb Diet If you…
Have Adrenal Dysfunction
Low carbohydrate diets raise cortisol, one of the hormones secreted by the adrenal glands when you’re in a stressful situation. Low carbohydrate diets can also cause blood sugar to severely drop, a condition known as hypoglycemia. Prolonged hypoglycemia and extreme blood sugar fluctuations make your adrenals release too much cortisol too frequently as they consider these stressful situations.
The adrenals are two small glands that sit on top of your kidneys. They work with two other glands, the hypothalamus and the pituitary, to maintain homeostasis or balance in your sympathetic nervous system. This system is responsible for your body’s fight-or-flight response to danger. All three glands influence and interact with each other in what is known as the HPA-axis (stands for hypothalamus-pituitary-adrenals).
When there’s too much cortisol secreted from the adrenals, the pituitary and hypothalamus glands will be suppressed. This is fine if the stress goes away, because the whole axis will reset. But a prolonged low carb diet that your body can’t handle is viewed as ‘stress’ and will lead to dysregulation and dysfunction in your HPA-axis.
Dysregulation in your HPA-axis can be the root of many issues. Symptoms like depression, fatigue, anxiety, hair loss, facial and body hair growth, headaches, dizziness, brain frog, poor memory, low libido, thyroid disorders, osteoporosis, PMS, dry or wrinkly skin, weight gain (or resistance to weight loss), water retention, bloating, sleep disturbances, mood changes, irregular periods, loss of periods (amenorrhea), heavy periods, and infertility are all related to hormone imbalances.
So if you already have too much stress in your life, whether you have a new job, house move, bills, your teenage kids, surgery, etc, it’s not the best time to try a very low carbohydrate diet. If you have been diagnosed with adrenal fatigue, have a higher or lower than normal cortisol level, or have some of the symptoms I just mentioned, it’s not the time for very low carb diet. Download the worksheet I created to help you calculate how much is right for you.
The hypothalamus and pituitary glands happen to interact with the thyroid gland as well in what is known as the HPT-axis. The hypothalamus releases thyrotropin-releasing hormone (TRH), which stimulates the release of thyroid-stimulating hormone (TSH) from the pituitary, which stimulates the release of thyroid hormone from the thyroid gland.
I just described how low blood sugar increases cortisol level which suppresses the function of the pituitary and hypothalamus glands. When these two glands don’t function optimally, the amount of thyroid hormone your thyroid gland produces may not be adequate.
If you have a thyroid condition, balancing blood sugar and insulin is very critical. Both hormone systems, insulin from the pancreas and thyroid hormone from the adrenal, affect each other. It’s important to prevent blood sugar spikes and crashes when you have a thyroid condition, so low-moderate carbohydrate intake is recommended. But, very low carbohydrate intake, 100 grams a day or less, is not recommended as you run the risk of hypoglycemia and inducing further stress.
If you don’t have hypothyroidism and start developing its symptoms while you’re on a low carb diet, get yourself tested and up your carbs. You can read more about hypothyroid symptoms and hypothyroid dietary management in my previous posts.
Are Pregnant, Nursing, an Athlete, or Lost Your Period
Low carb diets can affect fetus brain development. Nursing is already a strain on your body and you need enough nutrients to feed your baby. If you’re a recreational or professional athlete working out 5+ times a week, you need more carbohydrates to replenish your stores. Losing your period (amenohrea) or having menstrual cycles all over the place is a sign of adrenal, thyroid, and sex hormones imbalances.
Severe carbohydrate restriction can make all of these things worse. Keep your carbs at 150 carbs a day or 40% of your calories if any of those apply to you. This is still considered a low carb diet but not too low to the point it might harm you.
How Many Carbs Should you Eat a Day?
There are several ways to calculate how many carbs to eat a day. I created a worksheet to walk you through a step-by-step process to calculate the amount that is right for you. Click HERE or use this box below to download.
If you’re still having a hard time putting it all together, see how we can help you through a private consultation.
Side Effects of Very Low Carbohydrate Diets
There are short-term side effects to very low carb diets that are less than 50 grams carbohydrates a day. These include hypoglycaemia, dehydration, lethargy, acidosis, and gastrointestinal problems like acid reflux, diarrhea, or constipation. Work with someone qualified who can help you try this low level safely.
Have you tried eating a low carb diet? How did you benefit the most? What was your biggest challenge?