Sceptically Fit

23/06/2011

Make Mine a Martini

Filed under: Health and Nutrition — Tags: , , — Sceptically Me @ 22:52

Unfortunately no – delicious, but my budget doesn’t generally stretch that far.

Is alcohol healthy – the best collation of our current understanding of alcohol on the body is here: The Truth about Alcohol, Fat Loss and Muscle Growth .

What are some of the points to consider:

The fattening question – alcohol is a sugar, but sugar alcohols are processed differently by the body. It will use them first so anything you eat on top of the alcohol is more likely to be unused and therefore stored as fat (which is why the article above recommends eating protein when drinking). Interestingly – if you are going for a ketogenic diet, the sugar alcohols do not kick you out of ketosis the way normal sugars will.

Moderate alcohol appears to be healthy.

Moderate alcohol consumption improves insulin sensitivity, lowers triglyceride concentrations and improves glycemic control. Not only in healthy folks, but also in type 2 diabetes. There is no clear consensus on the insulin sensitizing mechanism of alcohol, but one viable explanation may be that alcohol promotes leanness by stimulating AMPK in skeletal muscle. It’s not a stretch to assume that this might have favorable effects on nutrient partitioning in the longer term.

If the effect of alcohol consumption on insulin sensitivity doesn’t impress you, then consider the fact that studies have consistently shown that moderate drinkers live longer than non-drinkers. This can be mainly attributed to a lowered risk of cardiovascular disease. However, alcohol also contributes to a healthier and disease-free life by protecting against Alzheimer’s disease, metabolic syndrome, rheumatoid arthritis, the common cold, different types of cancers, depression and many other Western diseases.

 

In terms of what to drink  the lower calorie per alcohol content is your best bet: Get Drunk Not Fat

I recommend a Gin, Soda Water, and two slices of lime.

 

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Gary Taubes – Good Calories, Bad Calories

Filed under: Health and Nutrition — Tags: , — Sceptically Me @ 18:20

I am currently reading Gary Taubes’ Good Calories, Bad Calories. I’ve been vaguely familiar with the idea of low carb diets for a while – and tried Atkins which was effective to both lose weight and regulate my crazy appetite though I didn’t follow it for very long or adhere to much more than the second phase during that time.I did read the Atkins diet at the time but didn’t really take much of the science in and skimmed all the personal testimonies so got through it very quickly without retaining much.

Recently, I’ve been getting more interested in understanding why things work or are good for us, as well as wanting to clean up my life (and how to properly). I read the Paleo Solution by Rob Wolf as I’d come across the idea of a paleo diet as a healthy eating lifestyle and reviews I’d read indicated that this was a good balance between easy reading and science. This is really about the problems of food we haven’t evolved to eat – eg gluten and lectin in grains, but also the issues of carbohydrate vs fat and protein consumption on our health. I’ll be looking further into the more paleo side of this later but it did drive me to look further into getting a better understanding of the science behind restricting carbohydrate consumption aside from the (pretty damn conclusive) fact that hunter-gatherer man did not eat a diet high in carbohydrates. I’m still working my way through the book, which covers both the science and the history of the competing studies, but I’m lead to believe this is a very good summary (I’ve only quoted the final findings):

Summary of Good Calories, Bad Calories by Greg of Guts and Black Stuff

1. Dietary fat does not cause obesity, heart disease or other chronic diseases.

2. Refined carbohydrates, through insulin secretion, do.

3. Sugars, especially those including fructose, are particularly harmful.

4. Refined carbohydrates are the dietary cause of heart disease and diabetes. They are the most likely (but not only) dietary cases of cancer, Alzheimer’s disease, and other chronic diseases.

5. Obesity is not caused by overeating or sedentary behavior.

6. Calorie restriction does not cause long-term weight loss, it causes hunger.

7. Fattening and obesity are caused by a hormonal imbalance, which can be driven by diet (e.g. insulin secretion).

8. Insulin is the primary regulator of fat storage.

9. Carbohydrate intake drives insulin, and is therefore proportional to our body composition.

10. Carbohydrates also increase hunger and decrease energy.

Female Athletes – eat more protein, eat less carbs

Filed under: Health and Nutrition — Tags: , , , , — Sceptically Me @ 17:14

I recently came across a study from 2006 looking at the dietary needs of women performing resistance exercises.  This study showed that women were less responsive to glycogen during exercise, less able to utilise carbohydrates for glycogen replenishment and required more protein then men post exercise. The advice from the study is that women should lower their carbohydrate consumption and increase protein and fat.

Nutritional aspects of women strength athletes

  • Less use of glycogen in women during resistance exercises (also sprints – yay HIIT)

For example, a repeated maximal knee extension protocol resulted in significant glycogen depletion in type I and II muscle fibres in trained and untrained men, but this was not found in women.An attenuated reduction in glycogen in women after resistance exercise is consistent with similar observations after sprint exerciseand may result from lower glycolytic enzyme activity in women or a suppressive effect of estradiol.This gender difference in carbohydrate metabolism during resistance exercise may also be explained by the fact that women usually have a greater capacity for lipid breakdown and oxidation compared to men, such that glycogen is spared more in women than in men.

  • Increased fat oxidisation post-exercise when doing resistance exercise rather than cardio. Carbohydrate demands post exercise are lower.

Immediately following resistance exercise in women, the respiratory exchange ratio (RER) significantly declines indicating an increase in fat oxidation during recovery.This significant decrease in RER post‐exercise has been noted by several investigators when resistance exercise was compared against sitting and against treadmill exercise with the same aerobic energy cost.  Elevations in fat oxidation post‐exercise spare exogenous carbohydrate for glycogen replenishment and underscore the importance of IMTG and dietary fat as an energy source.

  • Advice on carbohydrate consumption:

One reason that high carbohydrate diets are not optimal for women strength athletes relates to the finding that women use significantly less glycogen during resistance exercise than menand synthesise less glycogen in response to a given amount of dietary carbohydrate.

carbohydrates with low glycaemic indices should be chosen to reduce the risk factors for cardiovascular disease, stroke, and diabetes as observed in women who consume higher glycaemic carbohydrates. Low glycaemic carbohydrates are rich in dietary fibre and contain important micronutrients, such as iron and B vitamins. These micronutrients are commonly found to be suboptimal in diets of women athletesbased on evaluations of self‐reported food intake and some biochemical indices of mineral and vitamin status.Fruits, vegetables, brown rice, enriched whole grain breads, whole grain prepared cereals, rolled oats, beans, legumes, and sweet potatoes are good examples of low glycaemic carbohydrate foods that strength training women should consume.

  • Advice on protein consumption

Although studies are inconsistent with regards to gender differences in protein metabolism,there is some indication that leucine oxidation is greater in men, and women may oxidise less protein during exercise because they derive more of their exercise energy needs from fat.

An area of particular interest in protein nutrition is the concept of timing and the differences that may exist between genders. In contrast to men, women have an attenuated increase in muscle protein fractional synthetic rate when amino acids are provided after exercise, suggesting that women may need to consume more protein after resistance exercise in order to elicit the same anabolic environment.

  • Addressing health concerns of a high protein diet (quoted at length – my highlights)

High protein diets have long been criticised on the basis of deleterious effects on bone due to their greater acid load that requires neutralisation by calcium salts.Women are at increased risk of osteoporosis as they age, so any potential adverse effects on bone health should be avoided. However, the justification to limit protein based on this criticism may not be warranted. Using dual stable calcium isotopes to quantify calcium kinetics in women, Kerstetter et al found that a high protein diet did not have any negative effects on net bone balance. Further, a protein supplement (42 g protein, 24 g carbohydrate, 2 g fat) given to young women and men throughout a 6 month strength and conditioning program, increased insulin growth factor‐1 and serum bone alkaline phosphatase (indicating increased bone formation) compared to a carbohydrate supplement of equal caloric value. Dietary unprocessed sources of protein contain both calcium and phosphorus and can contribute to increased dietary calcium and phosphorus intake. High protein intake does not appear to have adverse consequences for bone health in females, but rather, may be beneficial. Another criticism of high protein diets is that habitual consumption in excess of recommended intakes promotes chronic renal disease through increased glomerular pressure and hyperfiltration. On the contrary, the effects of high protein diets consumed by healthy humans were recently reviewed and it was concluded that there is insufficient proof to limit protein intake for the purpose of preserving renal health in healthy adults. The Institute of Medicine has also concluded that there is no clear evidence indicating that high protein diets have other deleterious effects including increased risk of cancer or cardiovascular disease. The final most common criticism against high protein diets in relation to strength athletes is that increasing protein intake beyond the recommended level is unlikely to result in additional increases in lean tissue because there is a limit to the rate at which protein tissue can be accrued. The argument against this statement is that even if there is a limit to gains in lean mass with high protein ingestion, increasing evidence shows that dietary substitution of carbohydrate with protein results in a variety of favourable health effects including enhanced weight loss, reduction in truncal adipose tissue, optimal maintenance of blood glucose, and improved lipid profile.

  • Advice on fat consumption

women seem to rely less on glycogen for resistance exercise than men. Thus, high fat diets may be advantageous for women strength athletes to complement energy production derived from IMTG and circulating lipids while concurrently sparing muscle glycogen

Investigators have demonstrated that women endurance athletes in energy balance need to obtain at least 30% of their energy from dietary fat to ensure rapid replenishment of IMTG following exercise. If fat intake is sub‐optimal, there is continued IMTG depletion following exercise for up to 2 days, which may limit performance in subsequent exercise sessions.

Fat intake greater than 15% of energy from unprocessed sources may help to prevent the female athlete triad as its consumption will help attain energy balance, improve bone health, and avoid depressed sex hormone concentrations.

Starting now…again

Filed under: Personal — Tags: , , , — Sceptically Me @ 16:07

Over the last few years I really have turned my health and fitness around. I lost weight, started exercising regularly and started eating better. My approach was very haphazard, my only real goal was to be able to run for long enough to be able to run away from a serial killer/monster (yes, I decided to get fit after watching a horror movie) – initially 20 minutes then 60.

I’ve always played the psychological game against myself to ensure I could get somewhere. When I first joined the gym I promised myself I could eat as much as I wanted, and drink as much coffee as I felt like as long as I kept exercising. I was so new to it all my metabolism took off so much my daily bowl of brownies and ice cream had no effect on my weight loss.

But newbie gains eventually stop. Fitness levels stop increasing without direction and time is a limiting factor. This year I ran a half-marathon – but in the process of encouraging my ability I went crazy diet-wise and would spend most of my time eating garbage and remaining ravenously hungry which continued post-race.

In an attempt to get that under control, I decided to try a low-carb/paleo diet. I’ve done low-carb diets before and just like a lot of the literature says, I found them effective in regulating my appetite and steadying my blood sugar levels (the first time I tried Atkins after almost fainting on two occasions when heading out early without breakfast). It wasn’t quite the 30 day success that I’d originally intended and too nights out with friends nulled the avoid bread/pasta/pizza/cake thing when I was being good. But I’m edging towards my aim for a diet – heavy in non-starchy vegetables, high in protein and fat, low in starches/carbohydrates aiming to avoid wheat as much as possible. I think I’ve already given up on the the idea of avoiding dairy – as long as its not been poured over cereal, I’m inclined to think I’m adapted to digest it. Oh, and negatives of coffee are too inconsequential for how wonderful it is…

For future reference – I don’t intend to source any claim I make in a personal post.

22/06/2011

Dr Cordain – Knowledge of our Ancestral Diet

Filed under: Health and Nutrition — Tags: , , , , — Sceptically Me @ 07:23

 

Dr Cordain has responded to the inevitable but grains must be important claim based on lack of pre-history knowledge…

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