Smoking and Obesity

interesting comment in the Guardian today from the artist David Hockney on obesity....

Is there a link between the decline of smoking and the rise of obesity and diabetes? It's been suggested that with a previous "health" scare of fat being bad for you, they took it out of a lot of food and thus the flavour, and then, to give it some flavour, added sugar. This was 30 years ago. It turned out some fat was not only essential, it was good for the heart after all, but they have now given a lot of people a sweet tooth. This is why it is so appalling that there is no debate at all about smoking. Some people might be much better off smoking instead of nibbling. There are still 10 million smokers, now treated like very naughty children. It seems there is no free lunch, and the media and political elite look like the cause of it all, exaggerating constantly to people they seem to despise.

Your epigenetics make you fat

I think I have remarked before on this Trinity of sexy themes at the moment in research in health and fitness:

• Microbiome
• Mitochondria
• Epigenetics

This is one for the epigenetics thread:  remember you have genes but the key thing is which of those genes are turned on  and which are turned off.  You are not programmed by you DNA, it is far more complex than that - you have a complex set of switches that react to your environment.

And that applies to your obesity.  You are not programmed to be fat.  Even if you have certain genes that are associated with fatness, they can be overridden.  The environment, epigenetic factors, the signals that you send to your cells,  are so much more important.  So to the study:


Getting Active Blunts Fat Genes

Physical activity appears to dampen the effect of fat-increasing genes, while inactivity allows the genetic disposition to unfold, a longitudinal study found.

Each additional gene variant linked with increasing body mass index (BMI) was associated with a mean gain of 0.13 kg/m2 in BMI, according to Qibin Qi, PhD, from Harvard School of Public Health in Boston, and colleagues.

However, individuals who were most physically active saw a blunted genetic effect, with a mean increase of 0.08 kg/m2, while those watching more than 40 hours of TV per week had an accentuated effect, with a mean increase of 0.34 kg/m2.

Although the genetic effect on BMI was most pronounced at each extreme, it was less so with more benign lifestyles, researchers reported at the American Heart Association's Epidemiology and Prevention/Nutrition, Physical Activity and Metabolism (EPI/NPAM) meeting in San Diego.

For those in the lowest quintile of physical activity, the mean increase in BMI was 0.15 kg/m2 -- a number slightly higher than the reference mean gain associated with each gene variant.

For those who watched up to only one hour of TV per week, the mean gain in BMI was 0.08 kg/m2, the same as in the highest quintile of activity.
 

 You do not have to be fat.  Get up and move about a bit.

Back to the microbiota - impact of the type of dietary fat

So back to another sexy term.  Not epigenetics this time but the microbiome.  There are studies out there that show that the gut midrobiome of the obese differs from that of the lean (and fecal transplants from lean to obese can make them lose fat).   This study seems to show that saturated fats shift gut microbiota profiles toward those typical of obese individuals, and that dietary fatty acid saturation influences shifts in gut microbiota independently of changes in body mass.

Oh noes, don't tell me that my saturated fat bias is being challenged?

Gut bacteria profiles of Mus musculus at the phylum and family levels are influenced by saturation of dietary fatty acids.

Gut Microbiome and metabolic health

This is another study that points to the the relevance of your gut microbes to health.  The finding is that certain strains of microbe in the gut are associated with obesity-related Metabolic disorders.

Women With and Without Metabolic Disorder Differ in Their Gut Microbiota Composition

Lieberman on Obesity

Another one on sleep and obesity

Short sleep duration in association with CT-scanned abdominal fat areas

Shorter sleep duration is associated with higher BMI, WC and SFA in men. Further research is needed to explicate the biological mechanisms behind these relationships and to see whether interventions addressing inadequate sleep could treat or prevent obesity by taking gender differences into consideration.

I suppose I should go to bed now.   There have been lots of studies showing this association now.  The mechanisms might not be clear but there is certainly something here.

Sleep more and it is easier to lose wieght

Thanks to Matthew Clarke for pointing this out.


There is an interesting study in the International Journal of Obesity this month.  Lots of times in the past I've pointed to things  saying to get more sleep for lots of health reasons - inflammation, stress reduction etc.  I have just drafted up an  article on sleep and I talk about the signals that you give to your body.   Compromised sleep sends a signal that you are under threat....so you produce stress hormones to get you ready for the threat.....and chronically elevated stress hormones (cortisol etc) lead to all sorts of problems....including obesity.

This new study found that those who slept more were better at losing weight!   Lowered stress was also a success factor, although that is linked - sleep more a way of reducing stress.

Anyway, here is the abstract:

Impact of sleep, screen time, depression and stress on weight change in the intensive weight loss phase of the LIFE study

Background:

The LIFE study is a two-phase randomized clinical trial comparing two approaches to maintaining weight loss following guided weight loss. Phase I provided a nonrandomized intensive 6-month behavioral weight loss intervention to 472 obese (body mass index 30–50) adult participants. Phase II is the randomized weight loss maintenance portion of the study. This paper focuses on Phase I measures of sleep, screen time, depression and stress.

Methods:

The Phase I intervention consisted of 22 group sessions led over 26 weeks by behavioral counselors. Recommendations included reducing dietary intake by 500 calories per day, adopting the Dietary Approaches to Stop Hypertension (DASH) dietary pattern and increasing physical exercise to at least 180 min per week. Measures reported here are sleep time, insomnia, screen time, depression and stress at entry and post-weight loss intervention follow-up.

Results:

The mean weight loss for all participants over the intensive Phase I weight loss intervention was 6.3 kg (s.d. 7.1). Sixty percent (N=285) of participants lost at least 4.5 kg (10 lbs) and were randomized into Phase II. Participants (N=472) attended a mean of 73.1% (s.d. 26.7) of sessions, completed 5.1 (s.d. 1.9) daily food records/week, and reported 195.1 min (s.d. 123.1) of exercise per week. Using logistic regression, sleep time (quadratic trend, P=0.030) and lower stress (P=0.024) at entry predicted success in the weight loss program, and lower stress predicted greater weight loss during Phase I (P=0.021). In addition, weight loss was significantly correlated with declines in stress (P=0.048) and depression (P=0.035).

Conclusion:

Results suggest that clinicians and investigators might consider targeting sleep, depression and stress as part of a behavioral weight loss intervention.

More on messed up sleep and obesity

Hot on the heels of that last study here is another.  It is again pointing to messed up sleep leading to messed up appetite and eating patterns.

The effect of sleep restriction on snacking behaviour during a week of simulated shiftwork.

Due to irregular working hours shiftworkers experience circadian disruption and sleep restriction. There is some evidence to indicate that these factors adversely affect health through changes in snacking behaviour. The aim of this study was to investigate the impact of sleep restriction, prior wake and circadian phase on snacking behaviour during a week of simulated shiftwork. Twenty-four healthy males (age: 22.0±3.6 years, mean±SD) lived in a sleep laboratory for 12 consecutive days. Participants were assigned to one of two schedules: a moderate sleep restriction condition (n=10) equivalent to a 6-h sleep opportunity per 24h or a severe sleep restriction condition (n=14) equivalent to a 4-h sleep opportunity per 24h. In both conditions, sleep/wake episodes occurred 4h later each day to simulate a rotating shiftwork pattern. While living in the laboratory, participants were served three meals and were provided with either five (moderate sleep restriction condition) or six (severe sleep restriction condition) snack opportunities daily. Snack choice was recorded at each opportunity and assigned to a category (sweet, savoury or healthy) based on the content of the snack. Data were analysed using a Generalised Estimating Equations approach. Analyses show a significant effect of sleep restriction condition on overall and sweet snack consumption. The odds of consuming a snack were significantly greater in the severe sleep restriction condition (P<0.05) compared to the moderate sleep restriction condition. In particular, the odds of choosing a sweet snack were significantly increased in the severe sleep restriction condition (P<0.05). Shiftworkers who are severely sleep restricted may be at risk of obesity and related health disorders due to elevated snack consumption and unhealthy snack choice. To further understand the impact of sleep restriction on snacking behaviour, future studies should examine physiological, psychological and environmental motivators.

A vicious circle of stress

Stress can make you fat – and being obese can create stress.

A vicious circle of stress

Getting fatter can potentially trigger the stress response, which in turn encourages additional weight gain.

"When you go up in weight, your body also comes under stress. That probably has a self-reinforcing effect – so you get even fatter," Foss explains.

But dieting can also stimulate cortisol production, which in turn may trigger the stress response and thereby counter the weight loss.

"Should our hypothesis turn out to be correct, it would mean that you'll have to break this stress pattern if you want to halt the weight increase," says Foss.

The paper is in medical hypotheses....

Stress in obesity: Cause or consequence?

Abstract

Obesity is a global public health challenge that increases the risk of various diseases including type 2 diabetes mellitus, hypertension and cancer, and will in the future cause further increases in the incidence of chronic disease. Understanding the mechanisms of obesity is critical if we are to prevent and treat this pandemic challenge. Diet and physical activity have traditionally been the major tasks in preventing and treating obesity. However, other mechanisms are now also being considered in the quest for knowledge and understanding of obesity, including the body’s stress system and cortisol release. While it seems evident that stress is a cause of obesity, whether stress is also a consequence of obesity has up to now only briefly been discussed. The aim of this article is to elucidate how stress and obesity might be linked and discuss the cause/consequence relationship between the stress response and obesity. Our hypothesis is that stress and obesity interfere by positive feedback. This may be an important issue in both our understanding and coping of obesity.

Lose weight...hacking your fat

interesting article in the New Scientist on lazy ways to lose weight:

• Get vaccinated - at least one common cold virus has been linked to obesity
• Avoid chronic stress
• Keep the temperature lower
• Stress a high protein diet
• Avoid plastic packaging, BPA etc
• Sleep in the dark, avoiding night light
• Avoid air pollution
• Have a lie in / get more sleep

It is interesting to read the whole thing: Eight lazy ways to lose weight

Some of those would be familiar to readers here - like the sleep in the dark.  Others are in Ferris's book the 4 Hour Body

Fatties (ok fat dogs) have lower body temperatures....

....this will encourage Matt Stone.



Association between obesity and reduced body temperature in dogs

Conclusion: These findings document an association between obesity and reduced body temperature in dogs and support the hypothesis that obesity in this and other species of homeotherms may result from an increase in metabolic efficiency achieved by a regulated lowering of body temperature.

More commentary here

Most humans and most animals gain weight because they accumulate fat. That occurs when they take in more energy than they expend. The unused energy is stored as fat.

"The way to reduce energy intake is to eat less, but that means you feel hungry, and a common way to increase energy expenditure is to exercise, but many people lack the motivation," he said.

Refinetti's study explored the theory that obesity may result from a less obvious reduction in energy expenditure: a reduction in body temperature. The idea is that warm-blooded animals spend much of their energy generating heat to keep the body warm. However, some animals have body temperatures that are naturally lower and therefore do not need to use as much energy to stay warm.

The reduced body temperature would be sufficient to account for body weight gain over several months.

"Although not yet replicated in humans, these results suggest that human obesity may be caused by a small reduction in the temperature at which the body maintains itself," he said.

Obesity - not just about energy balance

This looks like an interesting article!

Obesity and energy balance: is the tail wagging the dog?

We combine evidence from in vitro and in vivo experiments to formulate a perspective on obesity aetiology that emphasises metabolic flexibility and dietary composition rather than energy balance. Using this model, we question the direction of causation of reported associations between obesity and sleep duration or childhood growth. Our perspective generates new hypotheses, which can be tested to improve our understanding of the current obesity epidemic, and to identify novel strategies for prevention or treatment.

Does anyone have the full paper?  UPDATE - thanks to the peopel that sent the paper including That Paleo Guy and Paul Jaminet.  Thanks guys

Obesity may mean your muscles are less able to cope with your body weight....

or as the headline says:  obesity creates wimpy rats

"These results may explain why muscle strength and locomotion are impaired in obese humans, and hence perhaps why it is so difficult to lose excess weight and recover from obesity," said Schilder.

The researchers first demonstrated that troponin T expression varied with body weight during normal growth. Then they artificially increased the body weight of one group of rats by 30 percent using a custom-made weighted vest. Externally applied weight caused a shift in the muscle troponin T expression, matching that of animals whose actual body weight was 30 percent higher. In contrast, troponin T expression did not respond to a similar increase in body weight in the obese rats.

A fat gut shrivels your brain!

Great headline on this New Scientist piece!

A fat tummy shrivels your brain

Obesity is linked to an increased risk of type 2 diabetes, which is known to be associated with cognitive impairment. So Antonio Convit at the New York University School of Medicine wanted to see what impact obesity had on the physical structure of the brain. He used magnetic resonance imaging to compare the brains of 44 obese individuals with those of 19 lean people of similar age and background.

He found that obese individuals had more water in the amygdala - a part of the brain involved in eating behaviour. He also saw smaller orbitofrontal cortices in obese individuals, important for impulse control and also involved in feeding behaviour (Brain Research, in press). "It could mean that there are less neurons, or that those neurons are shrunken," says Convit.

Eric Stice at Oregon Research Institute, Eugene, thinks that the findings strengthen the "slippery slope" theory of obesity. "If you overeat, it appears to result in neural changes that increase the risk for future overeating," he says. Obesity is associated with a constant, low-level inflammation, which Convit thinks explains the change in brain size.

Does pollution make you fat?

I thought this was interesting:

Polluted air increases obesity risk in young animals

Animals exposed to the fine-particulate air pollution had larger and more fat cells in their abdominal area and higher blood sugar levels than did animals eating the same diet but breathing clean air.

It is not just diet or exercise or stress....the totality of your environment is important to health.....including the air you breathe.

Breathing to lose weight?

The "Senobi"

This one just looks weird!  It reckons that a basic breathing exercise can up regulate the output of certain hormones.

The whole paper is available as pdf

Here is the abstract:

The "Senobi" breathing exercise is recommended as first line treatment for obesity.
Sato K, Kawamura T, Yamagiwa S.

Neuroadrenergic abnormalities, including a predominant activity of parasympathetic nerve and blunted hormone secretion, are recognized in the overweight patients. This study aimed to examine whether the "Senobi" breathing method, a stretch-breathing exercise that we have developed, could activate or recover sympathetic nervous system activity that leads to the loss of body weight. Forty pre-menopausal women, aged 40 to 50 years, participated in this study. Twenty were healthy and the other 20 were overweight (body mass index > 25 and body fat > 30%). Sympathetic nerve activity was assessed using equipment that analyzes cardiac-beat variation, and several urinary hormone levels were examined before and 30 min after performing the "Senobi" breathing exercise. The average proportion of sympathetic nerve among healthy women during daytime hours (10 : 00 AM to 12 : 00 PM) was 62.6% ± 2.6%. On the other hand, that of overweight women was 33.5% ± 0.4%. After 1 min of the "Senobi" breathing, substantial up-regulation of sympathetic nerve activity and increased urinary hormone secretion were observed in the overweight women but not in the healthy controls. Moreover, after repeating the exercise for a month, the obese patients showed significant loss of body fat. The "Senobi" breathing exercise was found to be effective for weight loss in obesity possibly by regulating the autonomic nervous system and the hormone secretion.

Vitamin B3 is making you fat.....

This one caught my eye today.

If you pick up any packet of cereal you find it is enriched with vitamins:

Ingredients

Maize, Brown Sugar (Sugar, Molasses), Peanuts (7%), Sugar, Honey (2%), Barley Malt Flavouring, Salt, Niacin, Iron, Vitamin B6, Riboflavin (B2), Thiamin (B1), Folic Acid, Vitamin B12.

Some Chinese scientists have just done a study indicating that Niacin can mess up insulin sensitivity....and make you fat

A research team from China examined the role of excess nicotinamide in glucose metabolism using co-loading of glucose and nicotinamide test. They proved that excess niacin intake-induced biphasic response, i.e., insulin resistance in the early phase and hypoglycemia in the late phase, may be a primary cause for the increased appetite in obesity. Their study will be published on May 21, 2010 in the World Journal of Gastroenterology.

The study also revealed for the first time that the obesity prevalence among US children and adolescents increased in parallel with the increase of the per capita niacin consumption with a 10-year lag, in which niacin fortification-induced sharp increase in niacin contents in grain products may play a major role. Reducing niacin intake and facilitating niacin elimination through sweat-inducing physical activity may be a key factor in the prevention and treatment of obesity.

I've not been able to access the full article yet but I certainly think there are some interesting implications there. Especially the last bit - exercise and sweating is healthy too in that it gets rid of excess niacin.

Obesity and Madness

I can't resist this one. Obese people are more likely to be mental?

Good Grief.....you are not fat enough?!

Obese patients 'encouraged to put on weight to qualify for surgery'

This is sick. Why the heck is the NHS spending money on this anyway? I know the arguments that it is not their fault (they are victims) and that obesity causes lots of healthy problems (e.g. cancer) but surely there is no need to operate?

Fat kids

There was a bit of discussion on the radio this morning debating the "good news" that kids are not getting as fat as we thought they were.

Child obesity is levelling off - reports the BBC

Maybe they are drinking more full fat milk?

The thing is though that there is still a big problem, especially for kids from poorer families. A study I saw today concluded:

Childhood obesity and overweight prevalence among school-age children in England has stabilized in recent years, but children from lower socio-economic strata have not benefited from this trend. There is an urgent need to reduce socio-economic disparities in childhood overweight and obesity.

The Guardian had a good piece too:

If the calculations are correct, it is suggested that "only" about 30% of youngsters will be overweight or obese – and remarkably the government's revised target of reducing the scale of the problem to year 2000 levels by 2020 might well be achieved. That assumes no improvement in the situation over the next decade and still leaves obesity among young children at twice the level it was in 1990 – the baseline for all the calculations.