Healthy, obese men were given two different diets during their stay in the Rowett’s specialised Human Nutrition Unit. Both diets had a high protein content (30% of total energy value of the diet) but they differed in the amount of carbohydrate: One diet was low in carbohydrate (4%) and the other contained a moderate amount of carbohydrate (35% total energy value).
“Our volunteers found both diets to be equally palatable, but they felt less hungry on the high-protein low-carbohydrate diet compared with the diet which contained high-protein but moderate amounts of carbohydrate,” said Dr Alex Johnstone, the Rowett’s weight-loss expert who led the study.
“Weight loss during the two four week study periods was greater on the high-protein low-carbohydrate diet, averaging 6.3 kg per person, compared with 4.3 kg on the moderate carbohydrate diet,” said Dr Johnstone.
An important part of this study was to unravel the physiological mechanisms behind this type of diet. It is known that when people eat low carbohydrate diets, within a relatively short time their body has to switch from using glucose as a fuel to using something different called ketone bodies. Ketone bodies are appetite-suppressing and they may have an effect on the appetite centres in the brain. It’s also well known that protein itself is very good at making people feel full-up.
“In this study, we showed that on the high-protein low-carbohydrate diet the volunteers became ketogenic within 1-2 days of starting this diet and so it may be that high-protein, low-carbohydrate diets are particularly effective because of the combined effect of the protein and the ketone bodies,” said Dr Johnstone.
“We showed that the volunteers on the ketogenic diet reduced their energy intake without increasing their hunger and this was a very important factor in their ability to stick to the diet.”
Dr Johnstone sounds a note of caution about her findings: “A paper published last year from the same study showed that low carbohydrate diets may have consequences for the health of the gut by dramatically reducing the numbers of particular types of bacteria. So we will be looking in more detail at the complex way in which we respond to changes in our diet before we can say whether low-carbohydrate ketogenic diets are a suitable tool for everyone who wants to lose weight.”
When the phase of the study which involved the volunteers finished in October 2004, it attracted considerable interest because of its celebrity volunteer, Cameron Stout, who lost just over 12 kg during his nine week stay at the Rowett Institute. At the time, Cameron mentioned his surprise at not feeling hungry during the study and said he had adjusted to eating smaller portions. How does he feel now, three years later?
“I had a great experience with the nutrition study at the Rowett. The food was excellent and the staff looked after us very well. Because I have such an irregular lifestyle I don’t find it easy to stick rigidly to all that I learnt while I was at the Institute, but I try to make an effort most of the time. For me it was mainly about breaking bad habits – and I guess we all have food vices we need to deal with!” said Cameron.
For further information please contact Dr Sue Bird, KT Manager, Rowett Institute 01224 716668, 07711 093417. Alex Johnstone is available for interview – please contact Sue to book a slot.
Sue Bird | alfa
Nitric oxide-scavenging hydrogel developed for rheumatoid arthritis treatment
06.06.2019 | Pohang University of Science & Technology (POSTECH)
Infants later diagnosed with autism follow adults’ gaze, but seldom initiate joint attention
24.05.2019 | Schwedischer Forschungsrat - The Swedish Research Council
The well-known representation of chemical elements is just one example of how objects can be arranged and classified
The periodic table of elements that most chemistry books depict is only one special case. This tabular overview of the chemical elements, which goes back to...
Light can be used not only to measure materials’ properties, but also to change them. Especially interesting are those cases in which the function of a material can be modified, such as its ability to conduct electricity or to store information in its magnetic state. A team led by Andrea Cavalleri from the Max Planck Institute for the Structure and Dynamics of Matter in Hamburg used terahertz frequency light pulses to transform a non-ferroelectric material into a ferroelectric one.
Ferroelectricity is a state in which the constituent lattice “looks” in one specific direction, forming a macroscopic electrical polarisation. The ability to...
Researchers at TU Graz calculate the most accurate gravity field determination of the Earth using 1.16 billion satellite measurements. This yields valuable knowledge for climate research.
The Earth’s gravity fluctuates from place to place. Geodesists use this phenomenon to observe geodynamic and climatological processes. Using...
Discovery by Brazilian and US researchers could change the classification of two species, which appear more akin to jellyfish than was thought.
The tube anemone Isarachnanthus nocturnus is only 15 cm long but has the largest mitochondrial genome of any animal sequenced to date, with 80,923 base pairs....
Researchers at Chalmers University of Technology, Sweden, have discovered a completely new way of capturing, amplifying and linking light to matter at the nanolevel. Using a tiny box, built from stacked atomically thin material, they have succeeded in creating a type of feedback loop in which light and matter become one. The discovery, which was recently published in Nature Nanotechnology, opens up new possibilities in the world of nanophotonics.
Photonics is concerned with various means of using light. Fibre-optic communication is an example of photonics, as is the technology behind photodetectors and...
29.04.2019 | Event News
17.04.2019 | Event News
15.04.2019 | Event News
17.06.2019 | Information Technology
17.06.2019 | Earth Sciences
17.06.2019 | Ecology, The Environment and Conservation