Thursday 11 September 2014

Better results from low carb than lower fat.


 There's a lot of chatter over the pond and on t'internet about a recent study comparing low carbohydrate diet advice with reduced fat.

The work was led by Drs Bazanno and Hu of Tulane University, New Orleans and funded by the US National Institutes of Health. Its stated objective was
to examine the long-term effects of a diet low in carbohydrates, as compared to one low in fat, on cardiovascular disease risk factors, including blood pressure (BP), body weight and composition, serum lipids, plasma glucose, insulin, adipocytokines (adiponectin, leptin, resistin), and C-reactive protein (CRP) among obese adults.

Thursday 31 July 2014

Fruit vs Fruit Juice

As a low carb person I eat berries and sometimes an apple, but fruit juice to me is just a sugar solution. Fruit itself seems to be universally regarded as A Good Thing (TM) and although Robert Lustig has said "the vehicle is irrelevant" when talking about fructose, and admits that he doesn't want to be the guy to say fruit is bad, the reliance on fibre as a moderator is somewhat optimistic.

Saturday 19 July 2014

Overfeeding and weight loss on oil

Over 40 years ago a paper presented two studies on overfeeding with a high fat diet. I was drawn to read this by wanting to see how it compared with Sam Feltham's experiments and to address the general question about overeating on a low carb diet.

The paper is by German authors - Kasper, Thiel and Ehl - and may have suffered a little in translation as the two separate studies are somewhat intertwined. Well, here goes -

Wednesday 16 July 2014

All calories are not equal

I was recently drawn to read a report of a clinical trial of over-feeding, conducted by Bray et al of Pennington Biomedical Research Center. This was an inpatient study looking at the effect of protein on weight gain in people eating 40% more calories than required for maintenance of body weight.

This study was brought to my attention as evidence that the number of calories is more important than the composition of those calories, and it was said that "all the extra calories were from fat". On further examination I found that it actually shows something different.

Tuesday 1 April 2014

Atkins and 5 / 7 a day

Bit off fuss in the news this morning where a new study (statistical analysis) suggests that 7 a day "portions" of "fruit and veg" is better than the currently recommended 5 a day based on general mortality as well as death from cancer, heart disease and stroke.

In other words if you eat more vegetables and fruit you're less likely to die in a car accident. This may seem flippant but a) it is April 1st and b) that's what they're saying when looking at "all cause mortality"....
Death risk from any cause decreased as fruit and veg consumption increased. Risk of death by any cause was reduced by:
14% by eating one to three portions of fruit or veg per day
29% for three to five
36% for five to seven
42% for seven or more
Fresh vegetables had the strongest protective effect, followed by salad and then fruit.
Fruit juice conferred no benefit, while canned fruit appeared to increase the risk of death - possibly because it is stored in sugary syrup, say the researchers.
Let's not forget that " Potatoes and cassava don't count because they mainly contribute starch to the diet " - not that low carb eaters would be bothering with those things anyway.

So where does this leave the health concious low carb eater ? The good old 42 year old fad that is the Atkins diet usually catches some stick on these occasions, but let's remind ourselves of the facts that in Phase 1, the most restrictive, the current Atkins plan requires 12 to 15 grams of carbohydrate from foundation vegetables.

So is the Atkins diet compatible with 5-a-day or 7-a-day of vegetables (and fruit) ?

According to conventional wisdom dietitians a portion is 80 grams which I think originates from the World Health Organisation. 5 or 7 a day at 80 grams each is 400 to 560 grams a day. If the carbohydrate content is low enough, less than 5 grams per 100 grams of veg, then the limits of Atkins Phase 1 are not incompatible with 5 or even 7 a day :-

Grams / day of vegetables
Carbohydrate g/day400560
123.02.1
153.82.7
Carbs g/100g

[ Note for Americans - UK / EU labelling reports carbohydrates separately to fibre, effectively "net carbs", so these numbers are lower than you are used to. ]

Some example vegetables from Tesco.com :-
Carbs g/100g
Green beans3.2
Brussel sprouts4.1
Cauliflower3.0
Savoy cabbage4.1
Spinach1.6
Kale1.4
Mushroom0.4
Romaine lettuce1.7
Asparagus2.0
Broccoli1.8

Clearly it is possible to comply with 5-a-day of vegetables and 7-a-day too if you're careful to pick the right vegetables.  You may be able to add 80 grams of raspberries a day (3.7g of carbs) into your discretionary non-foundation veg carbs too, or as you move into Phase 2 the chocie of vegetables and berries will increase accordingly.

I conclude that the Atkins diet is entirely compatible with the "5 a day" message, in fact it's effectively built in with the 12-15g of carbs from foundation vegetables. Enjoy !


PS Full study behind the headlines is "Fruit and vegetable consumption and all-cause,
cancer and CVD mortality: analysis of Health Survey for England data" by
Oyinlola Oyebode, Vanessa Gordon-Dseagu, Alice Walker, Jennifer S Mindell.
To be found online, currently with Open Access.
JECH Online First, published on March 31, 2014 as 10.1136/jech-2013-203500


PPS You might be interested in an audio podcast about getting overweight children to eat more vegetables (and fruit).

Thursday 9 January 2014

Sugar

A lot of media fluster about sugar this morning, some single issue campaigning group trying to make out that a single substance or group of substances is behind the "obesity epidemic".

I'm sure these underemployed cardiologists have looked at the evidence, but the sugar consumption thing has always intrigued me as I used to make the stuff. In the UK we make / import about 2.5 million tonnes of sugar net of exports and it has been like this for 30 years or more. I must dig out those statistics.

Meanwhile I looked at a UK Govt food survey statistical digest and pulled out the data below :-
I have also been reading a paper from 1995 which observed that ..
The prevalence of clinical obesity in Britain has doubled in the past decade.....  However, average recorded energy intake in Britain has declined substantially as obesity rates have escalated.
So the fans of calorie restriction have a real problem. They can't blame obesity on gluttony, as several datasets and studies show that our calorie intake is declining. So they're left with sloth and assuming that we're all doing 1000 calories a day less activity (yeah, right) to justify the increase in obesity.

Likewise the fructophobic cardiologists, in remission from lipophobia, are going to struggle to explain the effect of declining sugar intake on increasing obesity.