Why Leafy Greens are Awesome for Weight Loss
Green leafy vegetables have been shown in studies to increase metabolism, reduce appetite and increase fat burning.
There are several mechanisms by which green leafy vegetables work to achieve this:
Thylakoids are membrane bound compartments which can be found in the chloroplast of the cell in green leafy veg.
The chloroplast is where photosynthesis takes place and is the part of the cell which makes the leaf GREEN.
Several studies have found that thylakoids are beneficial in reducing the appetite, increasing fat burning and other parameters of metabolic health.
A new study from Sweden found that after 90 days of consuming 5g spinach extract once per day, participants lost 5 kg (11 pounds) compared to 3.5 kg (7.7 pounds) in the control group.
Consumption of the spinach extract also reduced total and LDL-cholesterol (compared to control), increased after-meal release of GLP-1, (a satiety hormone) and decreased the urge for sweet and chocolate compared to the control group.
To release the thylakoids optimally it is necessary to crush, filter and centrifuge the leaves.
This is why green smoothies have such a good reputation as a weight loss tool.
It takes this blending process to release these beneficial thylakoids from their membranes.
Another researcher found that when humans were given a shot of the spinach water extract in the morning, they experienced less hunger and fewer food cravings throughout the day.
The participants who received the shot had higher satiety hormones in their blood, in addition to more stable blood glucose levels.
This finding was mirrored in another Swedish study which found that thylakoids in the diet reduced the hunger hormone ghrelin and increased the satiety hormone, leptin.
2.) Vitamin D and Calcium
Leafy greens are also high in vitamin D and calcium, both of which are known to be important for metabolism and body weight control.
Doctors in one study wanted to see what effect a breakfast with low or high levels of calcium and vitamin D would have on fat-burning and appetite later in the day.
When obese participants ate a breakfast containing 250 mg of calcium with 12 IU of vitamin D, or 500 mg of calcium with 348 IU of vitamin D; over the next 24 hours, those in the high-calcium/vitamin D group consumed 320 fewer calories than the low calcium/vitamin D group.
In addition, those in the high-calcium/vitamin D group had a higher metabolic rate, burned more calories and utilized fat better than the low-calcium/vitamin D group.
3.) Vitamin C
Leafy greens are also high in vitamin C.
Vitamin C has also been shown to play an important role in metabolic health and body weight control.
Many low carb dieters reduce their intake of fruit and are at risk of becoming deficient.
By upping the intake of green leafy veg, we can ensure that we are getting enough vitamin C to keep the metabolic benefits.
The most important way that vitamin C affects body weight and metabolism is via its effects on bile acid metabolism.
Bile acids have been shown to be important metabolic regulators.
The more bile acids we have, the more these important molecules are able to send their signals to the brain to boost metabolism, reduce the appetite and increase fat burning.
Vitamin C is required to convert cholesterol to bile acids.
If we don’t have enough vitamin C, we are not able to convert cholesterol to the metabolically regulating bile acids.
The other result of this reduction in conversion of cholesterol to bile acids is that cholesterol starts to build up in the liver and the blood.
The conversion of cholesterol to bile is an important mechanism by which cholesterol is kept at healthy levels and doesn’t build up.
This is why vitamin C deficiency leads to hypercholesterolemia and contributes to the development of atherosclerosis.
Consistent with this, it has been shown that vitamin C supplementation of 1000 mg per day has been shown to lead to significant decreases in fasting blood sugar, triglycerides, LDL, HBA1c and serum insulin. (The dose of 500mg was not enough to produce an effect).
These are all symptoms of dysfunction of the hypothalamus in the brain.
The hypothalamus also regulates appetite and body fat levels, and a dysfunctional hypothalamus would certainly mean more problems with appetite and body weight control.
Another study found that supplementation of at least 500 mg of vitamin C increased the amount of fat burnt during exercise by 39%!
So increasing vitamin C will mean that you get more bang for your buck when you exercise.
4.) Boosts the Intestinal Immune system
This is important because an enhanced immune system is better able to control over-growths of bacteria in the intestine, which damage bile acids leading to poor metabolic function and an increased appetite.
Australian researchers have determined that green leafy and cruciferous vegetables stimulate the immune system of the intestines by donating a gene that regulates the gut’s defence mechanisms.
This gene stimulates the development of innate lymphoid cells- which are very important players in intestinal immunity and the control of bacteria there.
Green leafy veg are also rich in polyphenols which have been shown to be antibacterial.
This would mean that leafy greens would also have a direct effect to reduce levels of bacteria in the intestine, thereby increasing bile acid signalling and metabolic health.
Green leafy veg improves metabolic health and appetite control via several mechanisms and is one of the best foods we have for correcting the body weight regulating system, when it goes wrong.
Beyond these factors, leafy and cruciferous greens also supply a whole spectrum of nutrients, including folate, iron, potassium, vitamin K, beta-carotene, lutein, zeaxanthin and others.
If we want to maximise weight loss and optimise health; including as much green leafy veg as we can should be a priority!
If you would like to read more of my take on diet and how it interacts with the body, to lead to weight loss or weight gain and poor health, you might want to sign up to receive my free Dietary Fat Report, which details my take on the effects of dietary fat on body weight-- the types, the amounts and the contexts of dietary fat intake are relevant to how it will affect your weight loss efforts).