Peter Grabowski

Peter Grabowski

I am a Registered Nutritionist (Nutrition Science) and Course Director of the Masters in Medical Science in Human Nutrition at the University of Sheffield, UK.

Location University of Sheffield, UK

Activity

  • Hi Audrey, about meat vs. fish - the survey shows that many people (especially men) are eating more red and processed meats than is recommended, while across the UK, the average consumption of oily fish is well below the recommended one portion (140g) per week in all age groups.

  • Public Health England (the executive agency of the UK Government's Department of Health) issued new recommendations about vitamin D to the public in July 2016, based on the findings of the SACN review (see step 3.7). There was press coverage at the time, but it might have been a little overshadowed by our change of Prime Minister and Andy Murray winning...

  • Hi Anne, peanut butter comes with a protein content of nearly 23 g per 100 g, so you can get around 3.5 g protein from a 15 g (tablespoon) portion.

  • April, you may be interested to hear that a study from researchers at the University of Aberdeen (Scotland) published in 2013 concluded that postmenopausal women who took holidays in sunny destinations abroad in the three months before they were assessed, had higher serum vitamin D levels than women who did not take holidays. There was also a lower prevalence...

  • Hi John, the full report (available through a link at the end of this step) shows that the committee did look at a wide range of non-musculoskeletal health outcomes too. For some outcomes there was evidence enough to conclude that there were no beneficial or detrimental effects of vitamin D, while for others they found that the evidence was inconclusive,...

  • Once the calcium levels in blood are back to normal, these mechanisms will switch off, so the loss from bone should not normally continue. The active form of vitamin D will also disappear much more quickly than the inactive form, so it does not stay around to cause trouble. In healthy young adults any calcium lost from the bones would be replaced very quickly...

  • Hi Dara, you've touched on a very important point - releasing calcium from the bones does weaken them. Throughout the day, the body works to keep our blood calcium levels within a tight range for nerves and muscles to work properly. If calcium levels drop too low, then we would start to have neuromuscular symptoms which could proceed to convulsions, arrythmia...

  • Hi Kevin, Thanks for your positive feedback and for your question of 19th Oct, which I have now responded to. The information source we have used for food composition is called "McCance and Widdowson's The Composition of Foods" from the Food Standards Agency and Public Health England. The tables are based on specific measurements that have been carried out,...

  • Hi Kevin, thanks for spotting the error in the pink salmon data - the per portion should read 13.6 mcg in a 100 g portion. The anomalies in the first five entries of the protein table are probably from rounding to the nearest gram of protein and to the nearest percent in the percentage column.

  • Hi Martha, Our data is extracted from food composition tables in "McCance and Widdowson's The Composition of Foods". Tables provide guide values based on measurements that have been carried out on particular batches of foods. The analytical laboratories assess samples from various sources and average the values, because composition will vary from source to...

  • Mothers who have low vitamin D levels can't pass enough on to their babies through breast milk and supplements are recommended. Barbara is right that vitamin supplements are made available for some people through the 'Healthy Start' scheme. In the 1930's it was difficult for clinicians to study the health benefit of new preparations of vitamin D in properly...

  • Hi Richard, The comment on fish bones is not so bizarre. Much of the calcium in canned fish is in the bones, and these small bones are edible and are considered safe to eat. The mineral part of the bones is dissolved by the stomach acid, the calcium that is released can then be absorbed in the intestine and the bone protein can then be digested in the same way...

  • Hi Silja, We didn't include spinach in the table because it might have be confusing to see a lot of calcium present (160 mg per 100 g) when in the text we say spinach is not a good source of calcium. The reason it is a poor source is that there is also a large amount of a natural chemical called oxalic acid present in spinach that binds up the calcium and...

  • Martha, I think your interpretation of 'varied' is what most people would consider. If we consume a broad range of foods over time we are more likely to be able to get all of the nutrients we need from our diet. If we were only to consume a restricted range of foods, then if those foods are lacking in one or more important nutrients we would be at risk of a...

  • Trish, a study from researchers at the University of Aberdeen (Scotland) published in 2013 concluded that postmenopausal women who took holidays in sunny destinations abroad in the three months before they were assessed, had higher serum vitamin D levels than women who did not take holidays. There was also a lower prevalence of vitamin D deficiency in the...

  • A number of participants have provided links to other national guidelines. For an overview of dietary guidelines from a wide range of countries across the globe you can visit the Food and Agricultural Organisation of the United Nations website at http://www.fao.org/nutrition/education/food-dietary-guidelines/home/en/ (some of the website is available in a...

  • I'm interested to see so many comments here saying that there is little information about the calcium and vitamin D content in packaged food labels, even on the products that we discussed as being good sources of these nutrients. Much of the compulsory nutrition information for food labelling is regulated because it relates to some very important public health...

  • There's a lot of enthusiasm for traffic light labelling and for larger printing of important information here. There is also some keen interest in what will happen about food labelling post-Brexit. The UK Government must serve notice under Article 50 to trigger a 2-year exit process and during that time the UK is still a member state of the EU. The EU will...

  • The tables we have given here are just a starting point for interest and discussion, and it's good to see mention of other foods that contain calcium that are not in the tables. Note also that we have focused on the calcium and vitamin D content of foods here because of their relevance to the musculoskeletal system - there are other nutrients in many of these...

  • There are some interesting questions on calcium supplements. For many people it is possible to get enough calcium through dietary sources, and you'll see some information in a later activity taken from the National Dietary and Nutrition Survey that shows this is the case for a large part of the UK population. Individual needs are determined by many factors...

  • Thanks Tom and Jeanne, we are not saying that a high protein/low carb diet is better, just that protein is important for muscle and bone maintenance, especially as we get older. Because we can't store protein in the body, we will lose it from our muscles and other organs if we don't get any in our diet, so it is important to have some protein rather than none...

  • The inactive vitamin D in the liver is a storage form, and to be able to function it needs to be activated by enzymes that are made in the kidney, but not in the liver to any great extent, in response to the release of parathyroid hormone. When Vitamin D is activated and eventually inactivated and eliminated, some of the vitamin D moves out of the liver...

  • Protein is protein whether it comes from plant or animal sources and most of us will be getting enough protein with a varied diet whether the proteins come from plant or animal sources. Because all proteins have a unique composition of amino acids, and because we can't make all of the amino acids in our bodies, the amino acid composition of the proteins we eat...

  • The question about physical activity level is not so easy to answer without measuring the basal metabolic rate and a good estimate of total energy expenditure, but it looks like many of you are pretty active - I would rate myself as sedentary to light and I know I need to do more exercise!

  • Thanks for the very positive feedback on the video - our animator did a great job. It is difficult to put a lot of detail into something like this so it's good to hear that it has been helpful in explaining the basic processes.

  • Hi Silja. we've included only a limited selection of foods in the tables, to give an idea of how the content of these nutrients varies between foods. You'll find calcium in lots of other foods, but we just couldn't list everything here.

  • Woops! This was meant to refer to calcium and phosphorus as minerals rather than elements.

  • We'll try to address some of the questions raised by participants as the week progresses.