I make no secret of my leaning towards high-protein, relatively low-carb diets. I am well aware of the relatively unhealthy reputation that such diets have. However, when one looks at the research one generally finds that the criticisms of such diet are based on theoretical and ideological concerns. They are not, generally speaking, based on what the science shows.
For example, it has long been said that protein is generally not good news for the bone. One reason for this is that the metabolism of protein makes the blood more acidic, which might have detrimental effects on the bone, partly because it believed to cause calcium to be leached from the bone. I can see why this might give protein a bad name regarding bone health, but protein also promotes bone health, at least in part because amino acids (the building blocks of protein). In the end, it’s not important what effect a nutrient or foodstuff has theoretically or on some marker or other ” the important thing is the impact it has on health.
So, if it’s bone health we’re interested in, it’s bone health we need to look at.
A group of British scientists recently performed a review of the available evidence regarding dietary protein and bone health, and this was published on-line in the American Journal of Clinical Nutrition [1]. To main types of study were used in this review; epidemiological and intervention. The epidemiological studies assessed the association between protein intake and bone mineral density (BMD) and/or bone mineral content (BMC). Some studies assessed the relationship between protein intake and risk of bone fracture.
The intervention studies involved giving individuals protein to see what effect this had on bone health. In this review, the outcome assessed was the BMD in the lumbar spine (lower back) and risk of hip fracture.
Taken as a whole, the epidemiological studies revealed that higher protein intakes were not associated with worse measures of bone health including BMD, BMC and risk of fracture. In fact, when amassed together, one type of epidemiological study (cross-sectional study) found higher protein intakes were associated with improved BMD.
The intervention studies followed suit ” protein supplementation was found to be associated with enhanced BMD. However, this did not appear to manifest itself as reduced fracture risk.
All in all, what is clear about this study is that it provides no support for the commonly-wielded criticism of high-protein diets regarding bone health. If anything, the totality of evidence shows that proteins richer in protein have benefits for bone.
References:
1. Darling AL, et al. Dietary protein and bone health: a systematic review and meta-analysis. Am J Clin Nutr 4th November 2009 [epub ahead of print]
When I first took a more critical look at dietary recommendations I was attracted towards the idea of a higher protein diet: its almost inevitable if you cut back on carbohydrates, especially if you are wary of fats, and saturated fats in particular have been demonised.
My understanding is that the body produces insulin in response to both carbohydrates (glucose) and protein (amino acids). Over time I have come to believe that a high fat diet is the way to go. The objective being to reduce the circulating insulin levels, and to make the body’s fat stores easily accessible as a souce of energy – which will reduce appetite and promote weight loss.
With natural wholefoods this is almost certainly a protein adequate diet, probably protein rich, diet. Certainly by comparison with the heavily promoted high carohydrate low fat diets generally advocated. Following a vegetarian diet is more problematic.
Some forms of protein appear to provoke a higher insulin repsonse than others: cassien being a case in point. In nature protein and fats are normally packaged together. Unfortunately modern farming, with its heavy reliance of grain feeding and fast growth has somewhat distorted the balance.
As has the trend towards leaner cuts and the reduction in consumption of organ meats.
My guess is that the best way to go is grass feed where meat is concerned, and eating the whole animal, not just the lean parts. Eating liver, kidneys, etc and using the bone sin broths will improve the vitmain and mineral profile of most diets. And perhaps a general mantra of quality over quantity would also help. Also, try and get good quality fats. Avoiding factory farmed foods is probably a good way to go – the diet will likely have a better vitamin and mineral profile. I think this is particularly important where fat soluable vitamins are concerned.
Another criticism also levelled at high protein diets is that they place stress on the kidneys. I would suggest that it is actually the high blood glucose levels resulting from a high carbohydrate load that are the problem for those with compromised glycemic control: a significant minority fo the population. Nevertheless I think its probably best to get protein alongside fat as nature probably intended rather than eating the protein rich parts of food in isolation.
My experience has been that where food is concerned nature is smarter than man; it is arogance that has caused a lot of taday’s health problems.
In reality most high protein diets are in fact high fat diets. That has to be true of any low carbohydate diet, where fat will be the dominant source of calories. Getting your protein alongside fat will blunt the insulin repsonse, slow absorbtion of nutrients, and provide a more satisfying and tasty diet.
Paul Anderson.
What is considered “high fat?” And, how does that affect weight and LDL levels? If one has both high blood sugars AND high LDLs, is a high sat fat diet still a good way to go?
The general recomendation is to eat around 30 percent of calories as fat, maybe 10-15 % as protein and the balance 50-55 % as carbohydrates.
I would regard a high fat diet as being maybe 60 or 70% fat with maybe 15-20% (calories) protein and carbs at 10% or less. Carbs would mainly be in the form of non starchy vegetables on a low carb diet.
If you have high blood sugars you need to get those down and you have to lower your intake of carbs to achieve that. Its difficult to raise protein above 25-30%. So to get carbs down fat consumption has to go up.
With regard to cholesterol I guess that probably depends on whether you believe the cholsesterol hypothesis and also whether or not you are having your LDL measured directly, and for particle size. Not all ldl is equal – some appears to be benign.
My guess is that saturated fat is far from being the villain its painted to be, and that the bad guys are sugar, fructose and unstable polyunsaturated fats. Just look at how thin people were before the advent of margarine and vegetable oils – depite eating lard, eggs, bacon, and butter. What’s the main change – people eat less fat, saturated especially, and have replaced the calories with vegetable oils, sugar and so called healthy wholegrains.
My thinking is that carbs turn in to blood sugar, fat doesn’t. Carbs raise insulin levels and inhibit the release of the body’s fat stores. FAt doesn’t. If you can’t access your stored fat – you feel hungry. The body can function without carbs. It can’t function without protein or fats. To lose weight you want to lose body fat. If you eat carbs it will be either used as energy – instead of the body’s fat stores, or converted in to fat: the exact opposite of what is required to lose weight. Losing weight on a low fat diet is a form of voluntary starvation. Whereas a low carb diet promotes an environemnt where the body switches to using fat as the main energy source.
That’s my simplistic view.
If you have blood sugar issues, by definition the body is having trounble processing carbohydrates. Why would you switch to a diet which emphasises the very macro nutrient the body is least well equipped to utilise? With fats and carbs its an either/or option.
If someone is having trouble losing weight or controlling blood sugar on the standard low fat diet I beleive the answer isn’t to eat even less fat, or do ever more prodigious amounts of exercise. Its worth looking to see if a lower carb or paleolithic type diet works better. there is mounting evidence to suggest it does, and often with beneficial changes in lipid profiles and other cardiovascular risk factors.
Paul Anderson.
Nancy,
An afterthought. What does the body do with excess blood sugar. It converts it in to body fat, which incidentally, is a saturated fat. To use and lose that body fat you have to create an environment whereby the body will switch to using is own fat stores as the preferential fuel source. In such circumstances it makes little sense consuming empty calories: sugars, starches, soft drinks, etc, and reality poor quality food sources such as bread and grains . One way or another your body needs to ustilise saturated fat in order to lose body fat as a souces of energy.
Paul Adderson.
Paul
What fats would you consider ok? I have always gone along the route of butter over marg and cutting out sugar (which I love!!!!!!). What is your opinion on cheese? I just love cheddar and wensleydale (good yorkshire lass). Even on a low carb intake it has taken me 2 months to lose 3lbs in weight. I do have underactive thyroid though.
Any comments most welcome.
Carol Homer
Please see extract taken from: The Paleo Diet Update: v5, #10 – Insulin Resistance from Fatty Acids. Issue: # 2009 – 10 / March 6, 2009
Insulin resistance is thought to be an important contributing factor to the modern diseases of civilization such as metabolic syndrome, blood lipid disorders, hypertension, obesity and type II diabetes.1 Although genetics play a role in insulin resistance, the observation that obesity and diabetes are increasing at alarming rates worldwide suggests that there are vital environmental factors that also need to be considered.2
Although carbohydrates play an integral role in insulin resistance by elevating glucose levels, there is also strong evidence that the amount and quality of free fatty acids consumed contributes to insulin sensitivity.3 It has been shown in rats that under certain circumstances, free fatty acids are required for glucose-stimulated insulin resistance. Essentially, when rats are infused with a high level of glucose, in the absence of fatty acids, the insulin response is non-existent.4 In contrast, when this occurs in the presence of high levels of free fatty acids, glucose-stimulated insulin resistance is extremely elevated. It was shown in these studies on rats that the amount of saturation of the fatty acid was also correlated with insulin secretion.5 The more saturated the fat, the higher the insulin burst. Thus, in rats, it seems that free fatty acids are vit al to produce glucose-stimulated insulin resistance, and, of these, saturated fats have the most detrimental effects.
Whether this occurs in humans was investigated by Vessby et al. (2001), who established that the amount and quality of fat in the diet could also be important for the development of insulin resistance in our species. A group of 162 healthy subjects were given an isocaloric diet high in either saturated or monounsaturated fat for three months. As in rats, insulin resistance depended on the amount of fatty acids consumed and the saturation of those fatty acids. When the amount of energy gained from fat was greater than 37%, it was found that insulin sensitivity was impaired in both the saturated fat group (-7.8%) and the monounsaturated fat group (-3.3%). However, when the amount of energy coming from fat was less than 37%, a significant difference was found with saturated fat still decreasing insulin sensitivity (-12.5%) and monounsaturated fat increasing it (+8.8%). Within the context of this study, it would seem that insulin resistance can be improved on a diet c onsisting of less than 37% of energy from fat, with this fat coming predominantly from monounsaturated fatty acids.
References:
1. DeFronzo RA, Ferrannini E (1991) Insulin resistance: a multifaceted syndrome responsible for NIDDM, obesity, hypertension, dyslipidemia and atherosclerotic cardiovascular disease. Diabetes Care 14: 173-194.
2. Seidell JS (2000) Obesity, insulin resistance and diabetes – a world wide epidemic? British Journal of Nutrition 83 (Suppl 1): S5-S8.
3. Evans JL, Goldfine ID, Maddux BA, Grodsky GM (2003) Are oxidative stress-activated signaling pathways mediators of insulin resistance and beta-cell dysfunction? Diabetes: 52(1): 1-8.
4. Stein DT, Esser V, Stevenson B, Lane KE, Whiteside JH, Daniels MB, Chen S & McGarry JD (1996) Essentiality of circulating fatty acids for glucose-stimulated insulin secretion in the fasted rat. Journal of Clincal Investigation 97: 2728-2735.
5. Stein DT, Stevenson BE, Chester MW, Basit M, Daniels MB, Turley SD & McGarry JD (1997) The insulinotropic potency of fatty acids is influenced profoundly by their chain length and degree of saturation. Journal of Clinical Investigation 100 (2): 398-403.
6. Vessby B, Uusitupa M, Hermansen, K, Riccardi G, Rivellese A, Tapsell LC, Nalsen C, Berglund L, Louheranta A, Rasmussen BM, Calvert GD, Maffetone A, Pedersen E, Gustafsson IB & Storlien LH (2001) Substituting dietary saturated for monounsaturated fat impairs insulin sensitivity in healthy men and women: the KANWU study. Diabetologia 44: 312-319.
Carol,
I have only recently, in the last 2 or 3 years, taken an interest in fats.
Generally you hear the three fat groups referred to: monosaturated, polyunsaturated and saturtaed fats. That is a gross simplification, as each of the categories have a large number of sub classifications. So not all saturated, monosataurated or polyunsaturated fats are equal.
I believe there are over 100 types of monosaturated fats and there are large numbers of saturated and polyunsaturated fats.
Its a huge area, as these are precursors to hormones, form cell structures, etc one which pays quite a bit of study – as well as being hugely interesting.
Coning back to what is healthy, I personally think fats that have stood the test of time are probably the healthiest.
For cooking you want stable fats – so lard, butter, coconut or macadami nut oil might be good choices.
Personally I love cheese but I am not sure how healthy it is. Certainly its calorie dense and I have seen suggestion the casien, the protein element, greats a relatively high insulin load – suggesting to me that it should not be eaten too regularly unless you are looking to gain weight.
I would tend to look for whole foods: meats, eggs, oily fish, some nuts (watch those roasted in vegetablt oils) advocados, and eggs as sources of good fats. Coconut oil also has been associated with good health.
Avoid cooking with vegetable oils which are unstable at high temperatures.
Olive oil seems to be relatively neutral.
Fish oil has a large number of advocates and helps to balance ratios of omega 3 and onega 9 fats.
With regard to weight loss – I think that you need to maybe look at the quality of what you eat first, and quantity second.
It can be a mistake to focus on sugar – not that I am suggesting for one momnet that its a healthy food. You also need to look at straches, grains, fruit juice, fructose, etc. Its quite possible to eat very little sugar yet overload your body with glucose by eating large amounts of starches and grains. Potatoes are pretty much composed of glucose and water for example, and a baked potato or mashed potato has a much higher glycemic indes than table sugar.
Some food for thought maybe.
Paul Anderson.
If you wnated to list the sort of foods you eat on a regular basis as well as an example of quantities I would be happy to comment. Don’t overlook calories drunk!