Do Fad Diets Work?
We hear about fad diets all the time, from everything to the lemonade diet, to raw veganism, to the so-called "alkaline diet." This blog post will attempt to help you determine fact from fiction and will explain what science says about diet, as well as what the internet quacks say. So let's begin!
Disclaimer: I am not a certified dietitian. you should always follow the advice of a doctor before starting a new diet or exercise regimen. That being said, all the factual information on this post comes from either registered dietitians, the government, or people with a PhD. I didn't just make it up.
The "Alkaline Foods" Diet
This particular diet is paraded around by celebrities as the greatest thing since sliced bread. The basic premise of the diet is that foods like meat, bread, sugar, etc, make the blood too acidic and causes you to become overweight, fatigued, bloated, etc. If you just buy their product, gurus say, you'll already be on the way to becoming a healthier, more alkaline person.
Uh, no. Just...no. This gif describes my reaction to these claims perfectly if you substitute "digestion" for "the Force."
First of all, anyone who took middle school science knows that the stomach is incredibly acidic. In fact, it secretes hydrochloric acid so that the pH is somewhere in the 1-3 range. That's incredibly acidic, being that the lowest pH possible on the scale is 1 and pretty much the only thing that's more acidic than that is battery acid. It must be this acidic because intense acidity denatures proteins for digestion in the small intestine and activates the proenzyme pepsinogen, which turns into pepsin, which is needed to break down proteins when activated. Other enzymes such as gastric lipase, which breaks down lipids, also work at lower pHs. To protect itself from this acidic environment, the stomach walls are lined with a thick, snot-like mucus that contains buffer in the form of HCO3-. "Buffer" is a chemical that, when added to another chemical with an extreme pH, changes the pH of the entire solution to a more neutral one. In this way, the HCL in your stomach doesn't eat holes in the lining. However, the HCL in the gastric juices of the stomach completely acidify all the digesta that enters it. What does this mean? ALL THE FOOD IN YOUR STOMACH IS THE SAME pH NO MATTER WHAT pH IT WAS WHEN YOU ATE IT. Eating "alkaline foods" or only drinking "alkaline water" does absolutely nothing to the pH of your blood because once the acidic food passes through your pyloric sphincter and into the duodenum of your small intestine, the pancreas and intestinal lining secrete even more buffer into the food until it's all essentially neutral in pH. At this point, enterocytes absorb the digesta and it enters the blood. Now, there are certain foods which, when digested, leave a substance called "ash." This is where the health gurus get it even more wrong. there are "alkaline ash" foods, which include fruits, veggies, etc. "Acidic ash" foods include animal products, beans, whole grans, and seeds. The gurus say if you avoid these "acidic ash" foods, you'll be automatically healthy. This is ridiculous. The only bodily fluid pH these foods affect is the urine. See, the body is an expert at maintaining internal equilibrium. If it wasn't, you'd die. In fact, urine is the only bodily fluid whose pH can change based on diet (1). Not blood. Your kidneys take care of that for you. In fact, blood pH is as easily regulated as taking a breath. Want to know why it's so uncomfortable to hold your breath? It's because when you hold your breath, CO2 starts to accumulate in the blood because you aren't breathing it out. This acidifies your blood, and you experience some discomfort and may even pass out. This forces you to take a breath, and your blood pH returns to normal as the circulatory system is flooded with fresh, clean oxygen (1). Similarly, if you eat too much protein, the amino acids absorbed by the enterocytes from the small intestine are converted to organic acids that might acidify the blood if the body wasn't so darn clever. It pulls calcium from the bones to use as a buffer to return the pH to normal. This phenomenon has been paraded around by the vegan community as a reason for you to avoid the evil, cruel goodness that is meat, since some studies have claimed that this calcium leaching may contribute to osteoporosis. However, according to a paper published in the Journal of Nutrition called "Do Protein and Phosphorous cause Calcium Loss?" (2) by Spencer, Kramer, and Osis, studies claiming this link between animal products and osteoporosis used only purified proteins and amino acids in purified diets. When long-term studies were done on adults who consumed as much as an entire pound of meat a day for as long as four months on end, urinary calcium didn't change in a significant way. Any calcium that was leached from bones and not replenished would be filtered out of the blood by the kidneys and excreted as urine if it wasn't retained to go back into the bones eventually. If it wasn't, blood calcium levels would be astronomical, which obviously wasn't the case or the test subjects would be dead. So why the difference between purified diets and more realistic diets? Phosphorous. Animal products like beef are high in phosphorous, which causes the body to retain calcium instead of excreting it. Therefore, those that claim that milk and meat give you osteoporosis because they make your blood acidic are wrong. My point is this: NOTHING YOU EAT WILL CHANGE THE pH OF YOUR BLOOD.
Then why do people see results with this diet? Simple. On this diet, you can't eat a Big Mac with large fries and a large glass of coke. It emphasizes a diet of mainly raw fruits and vegetables, which will undeniably lower your calorie intake significantly, and cause you to lose weight because it takes a LOT of energy to digest the cellulose in raw plant foods. In fact, there are plant foods like raw celery and broccoli which have negative calorie values, meaning it takes more calories to digest them than they provide when converted to ATP (the form of energy the body uses to run itself). The "alkaline" diet cuts out pretty much all animal products. and when combined with plenty of exercise, weight loss occurs. And because you're finally eating your veggies, you become healthier. Any success achieved by this diet is due to this fact, not because your blood is "alkaline." Case closed.
The "Lemonade Diet"
Of all the diets out there, this is one of the stupidest. Basically, all you consume is lemon water, water, maple syrup, and cayenne pepper for ten days straight in order to "detox" your body. I think this gif sums up how I feel about the internet gurus who promote this crap:
Uh, no. Please no. There's so much wrong with this diet I had trouble figuring out where to begin. For starters, literally the only macronutrient this diet supplies is sugar. and not even in the form of carbohydrates, which the body needs for energy. No, the sugar supplied in this diet is mainly sucrose and fructose, which are both monosaccharides and aren't as energy-dense as carbs. It will give you energy, but not for long. Eventually, you'll sugar crash. and while cayenne and lemon might provide some health benefits on their own, this is basically a fast, not a diet. You'll lose weight on this diet, but that's because you're not EATING! There's no source of protein or fats in this diet. Without protein, your muscles can't repair themselves. In fact, none of your body's tissues can repair themselves. This includes skin, bone, digestive tissue, and even blood. It could kill your immune system, and will make you feel weak. Without fats, cells can't divide because the membrane of every cell in your body is made of lipids. Desperate for nutrition, your body will tap into the fat you've stored in your body, and you'll lose weight. But not in any sort of healthy way at all. Need I continue debunking this diet? Don't do it if you don't want to starve to death (3).
Disclaimer: I am not a certified dietitian. you should always follow the advice of a doctor before starting a new diet or exercise regimen. That being said, all the factual information on this post comes from either registered dietitians, the government, or people with a PhD. I didn't just make it up.
The "Alkaline Foods" Diet
This particular diet is paraded around by celebrities as the greatest thing since sliced bread. The basic premise of the diet is that foods like meat, bread, sugar, etc, make the blood too acidic and causes you to become overweight, fatigued, bloated, etc. If you just buy their product, gurus say, you'll already be on the way to becoming a healthier, more alkaline person.
Uh, no. Just...no. This gif describes my reaction to these claims perfectly if you substitute "digestion" for "the Force."
 |
| Oh, Han. I understand your pain perfectly. |
First of all, anyone who took middle school science knows that the stomach is incredibly acidic. In fact, it secretes hydrochloric acid so that the pH is somewhere in the 1-3 range. That's incredibly acidic, being that the lowest pH possible on the scale is 1 and pretty much the only thing that's more acidic than that is battery acid. It must be this acidic because intense acidity denatures proteins for digestion in the small intestine and activates the proenzyme pepsinogen, which turns into pepsin, which is needed to break down proteins when activated. Other enzymes such as gastric lipase, which breaks down lipids, also work at lower pHs. To protect itself from this acidic environment, the stomach walls are lined with a thick, snot-like mucus that contains buffer in the form of HCO3-. "Buffer" is a chemical that, when added to another chemical with an extreme pH, changes the pH of the entire solution to a more neutral one. In this way, the HCL in your stomach doesn't eat holes in the lining. However, the HCL in the gastric juices of the stomach completely acidify all the digesta that enters it. What does this mean? ALL THE FOOD IN YOUR STOMACH IS THE SAME pH NO MATTER WHAT pH IT WAS WHEN YOU ATE IT. Eating "alkaline foods" or only drinking "alkaline water" does absolutely nothing to the pH of your blood because once the acidic food passes through your pyloric sphincter and into the duodenum of your small intestine, the pancreas and intestinal lining secrete even more buffer into the food until it's all essentially neutral in pH. At this point, enterocytes absorb the digesta and it enters the blood. Now, there are certain foods which, when digested, leave a substance called "ash." This is where the health gurus get it even more wrong. there are "alkaline ash" foods, which include fruits, veggies, etc. "Acidic ash" foods include animal products, beans, whole grans, and seeds. The gurus say if you avoid these "acidic ash" foods, you'll be automatically healthy. This is ridiculous. The only bodily fluid pH these foods affect is the urine. See, the body is an expert at maintaining internal equilibrium. If it wasn't, you'd die. In fact, urine is the only bodily fluid whose pH can change based on diet (1). Not blood. Your kidneys take care of that for you. In fact, blood pH is as easily regulated as taking a breath. Want to know why it's so uncomfortable to hold your breath? It's because when you hold your breath, CO2 starts to accumulate in the blood because you aren't breathing it out. This acidifies your blood, and you experience some discomfort and may even pass out. This forces you to take a breath, and your blood pH returns to normal as the circulatory system is flooded with fresh, clean oxygen (1). Similarly, if you eat too much protein, the amino acids absorbed by the enterocytes from the small intestine are converted to organic acids that might acidify the blood if the body wasn't so darn clever. It pulls calcium from the bones to use as a buffer to return the pH to normal. This phenomenon has been paraded around by the vegan community as a reason for you to avoid the evil, cruel goodness that is meat, since some studies have claimed that this calcium leaching may contribute to osteoporosis. However, according to a paper published in the Journal of Nutrition called "Do Protein and Phosphorous cause Calcium Loss?" (2) by Spencer, Kramer, and Osis, studies claiming this link between animal products and osteoporosis used only purified proteins and amino acids in purified diets. When long-term studies were done on adults who consumed as much as an entire pound of meat a day for as long as four months on end, urinary calcium didn't change in a significant way. Any calcium that was leached from bones and not replenished would be filtered out of the blood by the kidneys and excreted as urine if it wasn't retained to go back into the bones eventually. If it wasn't, blood calcium levels would be astronomical, which obviously wasn't the case or the test subjects would be dead. So why the difference between purified diets and more realistic diets? Phosphorous. Animal products like beef are high in phosphorous, which causes the body to retain calcium instead of excreting it. Therefore, those that claim that milk and meat give you osteoporosis because they make your blood acidic are wrong. My point is this: NOTHING YOU EAT WILL CHANGE THE pH OF YOUR BLOOD.
Then why do people see results with this diet? Simple. On this diet, you can't eat a Big Mac with large fries and a large glass of coke. It emphasizes a diet of mainly raw fruits and vegetables, which will undeniably lower your calorie intake significantly, and cause you to lose weight because it takes a LOT of energy to digest the cellulose in raw plant foods. In fact, there are plant foods like raw celery and broccoli which have negative calorie values, meaning it takes more calories to digest them than they provide when converted to ATP (the form of energy the body uses to run itself). The "alkaline" diet cuts out pretty much all animal products. and when combined with plenty of exercise, weight loss occurs. And because you're finally eating your veggies, you become healthier. Any success achieved by this diet is due to this fact, not because your blood is "alkaline." Case closed.
The "Lemonade Diet"
Of all the diets out there, this is one of the stupidest. Basically, all you consume is lemon water, water, maple syrup, and cayenne pepper for ten days straight in order to "detox" your body. I think this gif sums up how I feel about the internet gurus who promote this crap:
 |
| If I see a David Wolfe meme one more time... |
The Bottom Line?
ALWAYS talk to a registered dietitian or a doctor before starting a new diet. Please. No reputable nutritionist would EVER recommend these diets. If they do, that should send up a red flag. I don't care what useless crap Gwyneth Paltrow is peddling, or what that meme you saw on Facebook said. Alkaline diets do not cure cancer. Lemon water is not magical, and neither are cayenne pepper or cabbage soup or cutting whole food groups from your diet. Here's a picture of the food pyramid just in case you're still confused. I hope this was helpful and eye-opening. Thanks for reading!
Sources
(2) http://web.b.ebscohost.com/ehost/pdfviewer/pdfviewer?vid=1&sid=c9b95a4f-c0e5-4ebb-a64c-ed6409f547a4%40sessionmgr104
I'm a full-time college student at Texas A&M University, where I'm in the process of getting my Animal Science degree, with eventual aspirations to go to law school and work as a consulting lawyer for agriculture corporations. I grew up around animals, and currently manage an operation that breeds show-quality boer goats for 4H and FFA exhibitors. My family also raises commercial cattle in south Texas.
I'm a full-time college student at Texas A&M University, where I'm in the process of getting my Animal Science degree, with eventual aspirations to go to law school and work as a consulting lawyer for agriculture corporations. I grew up around animals, and currently manage an operation that breeds show-quality boer goats for 4H and FFA exhibitors. My family also raises commercial cattle in south Texas.
Comments
Post a Comment