Isotope evidence of meat consumption in our early ancestors December 30, 2008
Posted by Dr Dan in paleo diet.4 comments
The C13/C12 isotope ratio in fossil remains is indicative of diet, specifically it tells us if we ate animals that consumed broad leaf plant material or grasses. This is because trees, plants and shrubs tend to discriminate against the heavier C13 carbon isotope during photosynthesis, compared with the grasses which don’t. Animals that then eat these plants retain that carbon signature. So by looking at this carbon signature in fossils it tells us whether our early ancestors ate animals that ate more grass (higher C13 ratio) or more plants (lower C13 ratio).
Studies on a 3 million year old hominid from South Africa shows that this individual ate large quantities of C13 enriched foods (grasses). It could be argued that we did not eat animals that ate grass, but rather the grass itself. However, because hominids have no biological capacity to digest grasses, and no microwear patterns on the teeth were observed indicating that grass was chewed, it is most likely that hominids ate the grazers of the grasses. The fact that the ratio was leaning towards grasses also suggests that the diet was predominantly from animals, that grazed on grass, rather than from eating predominantly broad leafed plants – if we were vegetarian and ate broad leafed plants you would expect a low C13 ratio.
Interestingly, this shift to open grassland foraging would have coincided with the sudden worldwide expansion of grasses 6 million years ago which is linked to a decrease in atmospheric CO2. This change in grass also led to a massive change in global fauna with an increase and spread of grazing mammals. The grasses and the grazing mammals had a mutually beneficial relationship as the grass fed the mammals and the mammals consumed any shrubs, bush or trees preventing them from turning the grassland into forest. It was this change that would likely have significantly contributed to the evolution of humans (having to walk upright, hunt meat etc).
Food and Nutrition
No pics today. I am trying intermittent fasting and am finding it relatively easy. I got the idea from Free the Animal,Conditioning Research and the IF Life. This makes sense in terms of paleo eating because many hunter gatherer groups eat one big meal a day and so in essence they are doing intermittent fasting. I didn’t eat until 5pm today and I had some spaghetti-less bolognese. In other words I ate ground beef in a tomato sauce. Then I had a mango and an avocado. Glad to see my weight is dropping down too. Phew. I will be having the big new year run down post and what I have learn’t over this christmas period. Coming soon.
Aborigines return to hunting and gathering and lose modern diseases of civilisation December 29, 2008
Posted by Dr Dan in paleo diet.Tags: aborigines, diabetes, fat, paleo diet
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In a study in 1984, by O’Dea in Diabetes, urbanised diabetic aborigines returned back to their hunter gatherer roots and their health was monitored. The subjects showed improvements in the metabolic abnormalities of diabetes, but also in several risk factors for cardiovasular disease, including a reduction in hyperlipidaemia, blood pressure, and prolongation in bleeding time. These changes occurred while eating a diet predominantly based from wild game animals. The diet was low in fat (13% energy), with the meat from wild game been very lean and consisting of only 1-2% fat most of which was monounsaturated fats. For more information on the diet of this group see this post.
Food
Today I decided I would eat one big meal and would only have small meals in between. I actually managed well and didn’t get hungry until 3pm when I made some guacamole (avocado, lemon juice, olive oil) and added some tomatoes.
For dinner I had roast pork shoulder with some cabbage that I simmered for an hour with onion, tomatoe paste, a bay leaf, white vinegar and olive oil. Later on I had a mango.
Nutrition and Exercise
Im getting back into things after christmas. So all is well now. I will post more about this tomorrow.
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The High Protein Diet of the Australian Aborigine December 24, 2008
Posted by Dr Dan in paleo diet.Tags: Aborigine, Dr Loren Cordain, paleo diet
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One of the most studied hunter gatherer groups alive today are the Australian Aborigines. Traditional aborigines are omnivores and the proportion of foods from animals and plants depends very much on season and geographic location. In general woman provided the subsistence diet, which consisted of gathering plant foods, honey, eggs, small reptiles, mammals, fish, shellfish, crustaceans, grubs and insects. The men provided the ‘feast’ aspect of the diet providing large mammals (i.e Kangaroos).
There was typically one meal a day in late afternoon when all the group would return to camp to prepare and cook the respective meal. Consumption of up to 3 kg of meat was not uncommon in one sitting. Consumption of snacks occurred for the remainder of the time and typically was comprised of insects, honey, grubs, wild fruit, nuts and the liver would often be eaten on the spot after a kill of large mammals. The amount of energy gained per day was very low at around 1200 calories of which animals contributed 64% of energy. The diet composition in terms of energy was 54% protein, 13% fat, and 33% carbohydrates. These figures are amazingly close to those predicted by Dr Loren Cordain.
Food
I will be posting my food shortly. It is christmas today and so will be difficult to get shots. So will resume again tomorrow!
Sleep Deprivation Makes You Fat December 24, 2008
Posted by Dr Dan in Omega 3, paleo diet.Tags: barry sears, low carb diet, paleo diet, sleep deprivation, the zone
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In todays society people are getting less and less sleep. Unfortunately, getting less sleep causes our body to become stressed and a byproduct of this is an increase in the production of the hormone cortisol. High levels of cortisol leads to an increase in insulin resistance, which results in increased insulin levels. This of course results in our bodies storing more fat. For further information on how this occurs read this post. Increases in insulin drives our blood sugar levels down and the most common way people rectify this is by eating more carbohydrates, which results in more insulin production and further fat storage.
Even a few hours of sleep deprivation results in significantly increased cortisol levels. A good diet can overcome this. Barry Sears, author of the zone, did a mini study as outlined in his new book ‘toxic fat’. He looked at medical interns who were about to begin a two week period of sleep deprivation on the medical wards. During this time they got approximately four hours of sleep a night. He split the interns into two groups – one group received a zone type diet (lean protein, vegetables, fruits and unrefined carbs) along with Omega 3 tablets (2.5g of EPA and DHA everyday) while the other group ate normally. After two weeks those interns on a zone diet (low carb) lost weight and showed improved blood lipid levels while the other group gained weight, and their cholesterol and triglyceride levels increased.
This is most likely attributable to the low carb zone diet lowering insulin levels and counteracting the negative effects of sleep deprivation, which causes an increase in insulin levels. Thus, another benefit of a paleo or low carb diet is that you are able to run on less sleep without some of the negative consequences. However, this is not recommended (by me) as everyone should aim to get plenty of the snooze. Another interesting aspect of the study found that those on the low carb diet had superior word recall at the end of the two weeks than the group eating normal foods. Thus, this type of diet seems to improve mental performance and this is most likely due to the increase in Omega 3’s.
On a side note I have just added my profile and you can see it here.
Carbohyrate Addiction December 22, 2008
Posted by Dr Dan in animal studies, carbohydrates.Tags: addiction, carbohydrates, sugar
4 comments
Carbohydrate addiction may be a bigger problem in our society than we suspect. It is very likely that diets high in carbohydrates cause us to become physiologically addicted to them. In a study in 2007, in France, cocaine addicted rats were offered super-sweetened water and within three days the rats swapped addictions to the sugar. Yes that correct sugar was more addictive to the rats than the cocaine was!!!!!!
Glucose activates similar dopamine receptors as cocaine. Dopamine is a neurotransmitter strongly associated with predicting a reward. Think Pavlov’s Dogs and how they salivate at the expectation of a food reward (in the case of Pavlov a ring of a bell). In nature we learn to repeat behaviours that lead to maximise rewards. In essence, it is not the reward itself that is addictive but the expectation of that reward. If carbohydrates strongly activate dopamine receptors then we may strongly expect a reward from carbohydrates, which enforces us to salivate and desire them. If cocaine is one of the most addictive substances known, and sugar causes a bigger addiction response than cocaine in rats, then humans should also become addicted to carbs, go into withdrawal if they can’t get it and the food industry ensures that it remains that way.
Food
I wasn’t really hungry in the morning so I had an avocado. For lunch I had some tarakihi fish fillets with lettuce, tomatoes, guacamole and courgettes. All dashed with loads of olive oil.
For dinner I was starting to get quite hungry. I made some more roast lamb with some boiled spinach.
Later on I had some more avocado.
Nutrition and Exercise
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No exercise today. Boo! But Im just glad my eating has been good for the last two days.
The Festive Season is Making Me Fatter December 21, 2008
Posted by Dr Dan in weight loss.Tags: paleo diet, weight loss
7 comments
So today was a depressing day. It was the first week I have gained weight and a large amount. I now weigh 106.8 kg and this is a 3 kg (6.6 pound) increase from last week. There are a couple of reasons as to why this would be the case. Firstly, my big carb weekend didn’t help much and my weight jumped up from that. Then on monday my friend came over from England and so we celebrated. Later in the week more celebrations because everyone was going on christmas holiday. So lots of alcohol kept my weight high. I have had some people comment on how this is the time to be jolly and to get back on the horse after the break. But psychologically it is hard to accept because up until now it has been plain sailing. It scares me that my weight has jumped up three kilograms. I know this is somewhat artificial because my body always bloats up after not sticking to paleo. But regardless it is still a jump up. But Im trying to see this as one battle lost, but many won, on my way to being thinner. I will respect myself more if I push past this and keep losing weight.
So what have I learn’t? A big load up on carbs is/was a terrible idea and really pushed my weight up quickly. I guess you can lose weight quickly on a paleo diet but you can gain it just as quickly when you resume eating carbs even if it is for two days. I have also learn’t that at most I should only drink alcohol once a week and even that is a lot. But as they say – back on the horse.
Food
Most of the day I did not feel hungry. So for lunch I had some blueberries just to tie me over.
For lunch I had some terakihi fish fillets in capers with bok choy cooked in ginger, garlic and butter.
But I was still hungry later and so I had some roast lamb and an avocado. I love lamb it has to be my favourite.
Nutrition and Exercise
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For exercise I didnt do much except vigorously vacuum, mop and broom the house. Which for a sunday is good enough for me.
The perfect human diet documentary preview December 20, 2008
Posted by Dr Dan in paleo diet, video.Tags: paleo diet, perfect human diet
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I have been lucky enough to talk to CJ Hunt who is in the process of filming a documentary based on paleo diet principles. It is titled ‘In Search of the Perfect Human Diet’. This diet changed his life as it has mine and many other people. For more information go to his website. This looks like the perfect diet documentary! He has also kindly agreed to answering some questions which I will post on here later. If anyone has any questions they would like asked let me know.
It looks GREAT!!!!! I can’t wait for it to come out.
Food
Sticking to Paleo. But due to the large festivities I have been going out a lot as well. For lunch I had some boiled eggs with a salad.
Here is some lamb stew I made for dinner. It included parsnips, carrots, courgettes (zuchinni), lamb.
Exercise
Me and my friend went to Karekare beach, which is about 20 mins from the major city centre – Auckland. With my new paleo exercise outlook I challenged my friend to stone throwing, shell throwing, long distance jumping and sprinting. It was a tie. I feel quite sore today. Here are some pics of the beach.
Mark Sisson’s New Book December 18, 2008
Posted by Dr Dan in Uncategorized.Tags: christmas, marksdailyapple, paleo diet
6 comments
If you want to read a review of Mark Sisson’s new book (at marksdailyapple) then read this post. It looks like it will be a great book!
Sorry for no post yesterday. My friend who I havn’t seen for years just came over from England and so we had drinks……too many drinks. I can see that this christmas is going to be a hard one to stick with Paleo. In fact this may be the first week I don’t lose weight (read – gain weight). But we will see on monday. I am determined to not stray from paleo until then.
How do we know what our paleolithic ancestors ate? December 17, 2008
Posted by Dr Dan in paleo diet.Tags: Dr Loren Cordain, hunter gatherer, paleo diet
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Its impossible to go back and study what our paleolithic ancestors ate. So how do we know? We use models, and the best models available to us are modern day hunter gatherers and anthropological evidence left over from the early part of the century. Unfortunately, the hunter gatherer mode of life is now almost extinct and this has never been subjected to a detailed analysis of dietary habits.
Neverthelss, a recent analysis of over 229 hunter gatherer societies by Dr Loren Cordain shows that the majority of these societies obtained between 55-65% of their energy from animal sources. No hunter gatherer society was above 86% reliance on plant foods and 11 hunter gatherer societies obtained greater than 86% of their energy from animal foods. A latitude effect was seen and showed a decreasing reliance on plant foods, and an increasing reliance on fish foods, the further you go towards the poles. The predicted macronutrient intakes based off this data was 22-40% carbohydrates (non-refined), 19-35% protein, and 28-47% fat.
So personally Im quite interested in those values. My macronutrient ratios are – 17% carbohydrates, 30% protein, and 52% fat. So clearly Im eating too much fat and not enough carbohydrates. But I fail to see how I could possibly get more carbs unless I up my intake of fruits or nuts. But overall, I think my ratio is somewhat near the atypical hunter gatherer. Of course my descent is that of hunter gatherers closer to the poles so I guess it is to be expected that my carb ratio is a little lower. But I might just try to up my carb intake a little but only with paleo foods.
Food
Well I cant turn away from those specials and today was no exception. Roast pork was so cheap so I bought a big slab of the stuff. But prior to that I had an avocado and a mango.
And then of course there is the pig. I had this with some lettuce and tomatoes. Both for lunch and for dinner.
Nutrition and Exercise
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For exercise I did 20 mins on the treadmill and sprinted about three times as fast as I could go. Unfortunately, I have now reached the upper limit of the speed level and so I will have to goto the sprint track near where I live. This will be better anyway as the treadmill takes awhile to get up to speed and so its not really an explosive burst of activity at the start like sprinting should involve.
Fat – the most efficient energy source December 16, 2008
Posted by Dr Dan in animal studies, carbohydrates, fat.Tags: birds, carbohydrates, fatty acids, ketone bodies
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Glucose, and therefore carbohydrates, have long been considered as the preferential and most efficient energy source in humans. Fatty acids tend to be seen as the back up, or a reserve, in case carbohydrates run out. But if birds are anything to go by this is a myth. Birds preferentially utilise fatty acids as an energy source over the less efficient carbohydrates. The reason why? Flight! Flying is probably the most energetically expensive activity an animal can undertake. Coupled with this is the fact that the bird cannot eat much as it will weigh it down making it very difficult to fly. Thus, birds must gain a large amount of energy from a small quantity of food. Fat fits the bill and provides the most efficient source of energy that can be jam packed into a small amount of space. Only when birds become flightless do you notice that their diet begins to shift to less energy dense food sources. As a result, birds are far more insulin resistant than mammals, and therefore us, having very high levels of fatty acids in their blood stream that can be drawn upon to be used as energy at any stage. Birds also show an increase in ketone bodies, which is comparable to mammals on a low carbohydrate diet (including us low carbers). So get maximum energy for your buck, give up on the less efficient carbs, and go for the energy efficient fat.
Food
So I went to the butchers this morning to get some bone marrow. He was very interested as to why I wanted marrow? I told him that I eat it and that it is very good for you as it is full of Omega 3’s – similar to fish oil. He commented that he always used to feed his dog marrow and that his dog lived for a very very long time. I told him it was the marrow. Anyway, for lunch I had some Marrow Soup. I got the butcher to cut the bone lengthwise. I then simmered the marrow in the slow cooker for about six hours with six cups of water, a bay leaf, peppercorns, a carrot, onion and zucchini. It was a bit weak and I would recommend using less water and more marrow if you try and make it.
For an afternoon snack I had some eggs, tomatoes and olive oil.
Then for dinner I had some blade steak boiled slowly with a can of tomatoes and paprika. I boiled it down so the sauce was nice and thick.
Nutrition and Exercise
I honestly forgot to put in the foods today. But Im just grateful I didn’t feast on carbs and managed to curb the cravings. In terms of exercise I realised I have not been taking advantage of where I live. In Auckland, New Zealand, I am literally surrounded by hundreds of beaches (from surf beaches to sheltered quiet bays), many volcanoes, off shore islands, rainforests, bird sanctuaries, marine reserves, mountains etc etc. Why am I not taking advantage of this? I have so much out their to play hunter gatherer with and Im been so boring in my exercise. So I am going to try and mix it up a bit and make the most of my environment.
