dangers of high protein dietBy Dr Joe

Just how safe is a high protein diet?
If you are considering going on a high protein diet, you are probably pondering the question: how safe is a high protein diet or put in another way, what are the dangers of a high protein diet?

Well, generally speaking high protein diets are safe. High protein diets aren’t new. Diets based around proteins have been around for ages in different formats.

On the whole high protein diets are effective for weight loss if the outline of the plan is easy and less confusing. This is important because the success of any weight loss plan is built around ease of use and incorporation into our busy lifestyles.

If you follow a well laid-out high protein diet weight loss plan like this one here on Amazon.com (if in Europe here on Amazon.co.uk), then a few adjustments here and there will give you the results you want…

…and you shouldn’t have any problems with safety of the high protein diet if you do as advised in the book.

But I have noticed that people have questions regarding the risks of high protein diets. Indeed there is justification about concerns regarding the dangers of high protein diets. Hence I felt providing answers to some of the questions relating to the dangers of the high protein diet would be something worthwhile.

So here we go.


Can a high protein diet be bad for you?

I have talked about how high protein diets can assist you to lose weight. Just like high protein diet can be good for weight loss, so can you have risks consuming high protein diets.

Yes, high protein diet does have some dangers. Looking at those disadvantages or dangers, you may conclude that high protein diet is bad for you. But just like everything in life you have the pros and cons. There are very few health interventions that don’t carry any risks, not least high protein diet.

It’s how you manage the risks or dangers associated with the high protein diet that will make the difference.

Can you gain weight on high protein diet when trying to lose weight?

Research has shown that anything in excess of the recommended daily protein allowance can in actual fact lead to weight gain if your diet is not structured properly.

> If you do not balance your carbohydrates and fats properly in line with the increase in protein content, then you are going to store the excess unused calories as fat. This is the exact opposite of what you are trying to achieve, if losing weight was your objective.


Don’t forget that a high protein diet can also be used for weight gain in scrawny individuals who wish to bulk up a bit.

High protein diets are a double-edged sword. You can swing a high protein diet in two opposite directions depending on what you want to achieve.

how safe is high protein diet

Can you get kidney strain and kidney stones from a high protein diet

Eating excessive amount of proteins puts a lot of strain on your kidneys. After the extra work load placed on your liver which has to deal with the excess protein, detoxifying it and rendering it into a useable format, it’s the turn of the kidneys to filter, launder the by-products of protein metabolism.

There is a chance your kidney function may depreciate over time if high protein diet is a long-term commitment.

Also, given the fact that a lot more calcium and oxalate are excreted on a high protein diet, there’s a chance you may form kidney stones on a high protein diet.

This is particularly so when your diet plan is mainly from animal proteins coupled with the fact that dehydration is an issue with high protein diets. This makes the risk of kidney stone high on a high protein diet.

Do high protein diets cause osteoporosis, bone loss (fragile bones)?

Following on from that, if you continue to lose a lot of calcium over a long time, you will mobilize calcium from your skeletal framework depriving your body of the much needed calcium. This is the concept of “peeing your bones out”.

But is it true that high protein diets actually cause osteoporosis? Is the relationship between protein and calcium an inverse one?

Not really?

What has long been accepted in the medical community is that high protein diets lead to increased excretion of calcium in the urine. That is not in question.

If you then apply the “peeing your bones out” concept that has also been a long-accepted phenomenon, it becomes logical that a high protein diet will lead to osteoporosis over time. This will make you prone to fractures as you get older, the longer you continue with the high protein diet.

But it isn’t as straightforward as that.

As far as protein intake and calcium excretion is concerned, the relationship is direct. The higher your protein intake, the more calcium you excrete in your urine. But is the excess calcium been excreted in the urine coming from the bones?

Recent studies seem to question that “peeing your bones out” thought process, as being not exactly true.

In fact, this review seems to actually suggest that low protein diets are more likely to cause osteoporosis (fragile bones) than a high protein one.

Here’s one conclusion they reached:

> “The long-term consequences of these low-protein diet–induced changes in mineral metabolism are not known, but the diet could be detrimental to skeletal health. Of concern are several recent epidemiologic studies that demonstrate reduced bone density and increased rates of bone loss in individuals habitually consuming low-protein diets”


That review even suggested that protein consumption at and below 0.8 g/kg body weight was associated with secondary hyperparathyroidism.

Hmm, interesting.

Confused? Don’t be.

The current thinking seems to be that increased protein intake even though leads to increased excretion of calcium in the urine, is matched by increased absorption of calcium from the gastrointestinal tract when your high protein food is digested.

So, nothing is lost. It doesn’t seem to be true that extra calcium is being mobilized from your bones when you consume a high protein diet.

A different relationship between protein and calcium absorption exists and it’s also a direct relationship. A high protein diet leads to a high calcium absorption from the gut. High protein intake equates to increased calcium absorption.

> The commonly held view that a diet high in protein and low in calcium can lead to a condition called osteoporosis (soft bone) is arguably no longer correct at least going by recent research findings.


It seems as if calcium supplementation is probably not absolutely necessary on a high protein diet as some studies suggest the supply will come from the diet itself.

plant proteins

Can a high protein diet cause cholesterol problems?

Consuming huge amounts of animal proteins certainly puts you at risk of developing high cholesterol. This is because animal proteins from meat and dairy do contain a lot of saturated fats and even trans fats as part of the food package.

> Both saturated fats and trans fats have the potential to cause your blood lipids to become unhealthy. High level of saturated fat is associated with high cholesterol, high triglycerides, high low density cholesterol (the bad cholesterol).


This is not always the case I must add, but the risk is there especially if your animal protein consumption is high. Of course, this will predispose you to heart attack and strokes.

However, plant proteins behave differently. They do the inverse thing. If you want to protect yourself from high cholesterol, then my suggestion is to have more plant proteins like beans, nuts, seeds, lentils as a big part of your protein package.

This review says “results from the Nurses’ Health Study suggest that eating more protein from beans, nuts, seeds, and the like, while cutting back on easily digested carbohydrates reduces the risk of heart disease.

In that study, eating more animal protein while cutting back on carbohydrates did not reduce heart disease risk, possibly because of the fats and other nutrients that come along (or don’t come along) with protein from animals”

There you have it.

Can you develop High blood pressure on high protein diet?

This springs from the earlier point. Saturated fats are associated with an increase in blood pressure.
This is based on some studies but the evidence is conflicting.

What is certain is animal proteins like meat and eggs do contain high levels of sulphur-containing amino acids. These sulphur compounds have to be dealt with somehow by the kidneys because they get converted to sulphuric acid.

The sulphuric acid has to be buffered by something alkaline. One alkaline of choice is calcium.

Continuously processing these sulphur-containing amino acids (the break down products of proteins) can lead to direct kidney damage over time.

Kidney damage inevitably results in blood pressure issues through a complex interaction that is beyond the scope of this article. That’s one way.

Another mechanism of high protein diet leading to hypertension is an indirect one. This is the fat in the animal food being consumed as protein. As you know food comes as a package. Most foods with animal proteins also have saturated fat.

This same review supports this concept.

It says “”Saturated fats from red meat and dairy products increase harmful LDL, but also increase HDL. A moderate intake of saturated fat (under 8% of daily calories) is compatible with a healthy diet, whereas consumption of greater amounts has been associated with cardiovascular disease”

The cardiovascular disease being referred to here are high blood pressure, heart attack and strokes.

No one is saying don’t eat animal proteins but as you can tell if you are going to get all of your high protein diet from animal sources, then you are going exceed the 8% that is being recommended.

> A high protein diet sourced from animal proteins will provide exceedingly high sulphur-containing amino acids (4 times higher than plant proteins) and very high saturated fats predisposing you to high blood pressure. Not good.


What’s the solution? Get most of your protein from plant sources.

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Does a high protein diet cause constipation?

People often ask if high protein diets cause constipation. The answer is, yes. High protein diets do have the side effect of constipation.

Why do high protein diets cause constipation? The reason why high protein diets cause constipation very is simple and covered by two words – dehydration and fiber.

Let explore how the side effect of constipation from high protein diet comes about?

3 explanations really.

The first is that high protein diet require a lot of work by the liver to process the amino acids absorbed from the gut. Processing nitrogenous substances which proteins have require a good dose of water to facilitate that metabolism.

Secondly, upon processing the amino acids, the waste products have to be filtered out by the kidneys. We have already established earlier on that the kidneys have to buffer sulphuric acid by-products of amino acid metabolism. That process also requires a good dose of water.

With so much water needed for those metabolic activities, dehydration is a high possibility.

Thirdly, a high protein diet that is sourced mainly from animal proteins has little or no fiber at all in it. Fiber aids regularity of bowel motions. With little fiber in your high protein diet, constipation is almost inevitable.

In this study from University of Connecticut, they found an inverse correlation between level of protein consumption and hydration. The more the protein content in your food, the more dehydrated you become.

The problem is people don’t realise this synergistic complication. They therefore do not drink more water to compensate, hence high protein dieters have constipation issues.

If you then add issue of exercise-induced dehydration to an already bad situation (because most dieters exercise which worsens dehydration), you can begin to see why constipation has a strong association with high protein use.

How do avoid constipation on a high protein diet?

The best way to avoid constipation when on a high protein diet is to drink more water. You will need to drink at least about 3 litres of water daily to avoid high protein diet constipation.

The second thing you do to get rid of constipation on a high protein diet is to increase your fiber intake. Adding high fiber vegetables will not ruin your high protein diet weight loss plan because those vegetables are very low in calories.

A third solution to avoiding or dealing with constipation problems on a high protein diet is to actually reduce the protein content of your weight loss plan. If you restructure the plan, you could still get the results you want without the headache of constipation issues.