Inside Health 28/2/17

8 GLASSES OF WATER

8 glasses of water a day
1945, US Food and Nutrition Board recommended 2.5 litres water a day. Qualified this by saying that it’s mostly contained within foods

water company advertised
“Healthcare professionals should be encouraged to talk with patients about the calorific content of SSBs [sugar sweetened beverages] when discussing lifestyle modification to manage overweight and/or obesity . . . Consumption of water in preference to other beverages should be highlighted as a simple step towards healthier hydration.” And healthier hydration is? “recommending 1.5 to 2 litres of water daily is the simplest and healthiest hydration advice you can give.”
NHS choices
The Eatwell Guide says we should drink six to eight glasses of fluid a day. Water, lower fat milk and sugar-free drinks including tea and coffee all count.

healthy adults who have free access to water – thirst is very potent at detectng tiny changes in fluid balance – kidneys balancing fluid by concentrating urine almost instantly and thirst to prevent dehydration –
thirst is not dehydration – clinical diagnosis

https://academic.oup.com/ndt/article/29/7/1377/1843525/Fluid-intake-and-all-cause-mortality
http://www.bmj.com/content/335/7633/1288
http://www.bmj.com/content/343/bmj.d4280
claims children dehydrated couple of years ago in press – just showed the children could concentrate urine
The results indicate that during free access to water humans become thirsty and drink before body fluid deficits develop, perhaps in response to subtle oropharyngeal cues, and so provide evidence for anticipatory thirst and drinking in man.

http://www.anaesthesiamcq.com/FluidBook/fl5_5.php

thirst is a very good predictor of needs in healthy adults
may be different if people have say dementia or children – may need special care

10,000 STEPS A DAY

JAMA fitness trackers 2016 – more weight gain with tracker than without over 2 years in addition to standard behavioural modifications
http://jamanetwork.com/journals/jama/article-abstract/2553448
NHS choices
“Setting yourself a target of walking 10,000 steps a day can be a fun way of increasing the amount of physical activity you do.
Sometimes overlooked as a form of exercise, walking can help you build stamina, burn excess calories and give you a healthier heart.
average 3-4000 steps per day”

http://www.bbc.co.uk/news/magazine-33154510

real lack of proof
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5225122/
‘However, many questions remain regarding the effectiveness of this technology for promoting behavior change. Behavior change techniques such as goal setting, feedback, rewards, and social factors are often included in fitness technology.’

‘The fitness tracker market is currently thriving, with estimates of almost 1.5 billion dollars in revenue last year alone’

 

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5225122/
FRUIT AND VEG A DAY
http://archive.senseaboutscience.org/pages/5-a-day-qa.html

launched 5 a day in 2003
WHO had recommended 400g fruit and veg a day – 5 portions

denmark 6 a day
http://www.ifava.org/about-ifava/our-members/denmark/
‘Prospective studies of fruit and vegetable intake and cardiovascular disease, total cancer and all-cause mortality were included.

There was a 8–16% reduction in the RR of coronary heart disease, 13–18% reduction in the RR of stroke, 8–13% reduction in the RR of cardiovascular disease, 3–4% reduction in the RR of total cancer and 10–15% reduction in the RR of all-cause mortality for each 200 g/day increment in intake of fruit, vegetables, and fruit and vegetables combined. In the nonlinear models, there were 16%, 28%, 22%, 13% and 27% reductions in the RR of coronary heart disease, stroke, cardiovascular disease, total cancer and all-cause mortality, respectively, for an intake of 500 g of fruits and vegetables per day vs 0–40 g/day, whereas an intake of 800 g/day was associated with 24%, 33%, 28%, 14% and 31% reductions in the RR, respectively.

For fruits and vegetables combined the lowest risk was observed at an intake of 550–600 g/day (7–7.5 servings/day) for total cancer, with little evidence of further reductions in risk with higher intakes, whereas for coronary heart disease, stroke, cardiovascular disease and all-cause mortality the lowest risk was observed at 800 g/day (10 servings/day), which was at the high end of the range of intake across studies.’

 
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4145465/

 

vast, vast majority of this type food studies are inherently little bit or lot unreliable – recall, not RCTs but cohort

 

One Response to “Inside Health 28/2/17”

  1. N Campling March 1, 2017 at 7:01 pm #

    10 a day! How do people eat so much? For breakfast, it’s a bowl of whole grain cereal with a portion each of dried fruit & fresh fruit. Then I have a main meal in the afternoon & that’s it. How do I get 5-6 portions of 80g / 3 heaped tablespoons of veg to fit onto my plate, as well as the protein & carbs? I have a piece of fruit & something sweet in the evening if I’m hungry, but normally don’t feel hungry ’til the next morning – how does anyone eat so much? (I’m 65 & have weighed the same for 25 years).