obesity

A pilot study involving 14 overweight or obese adults (average age 56) on a calorie-restricted diet, found that those whose diet had higher levels of protein showed greater improvements in their sleep score, regardless of the source of the protein.

In a follow-up study, 44 overweight or obese participants followed a normal-protein or a higher-protein weight loss diet (either 0.8 or 1.5 kg of protein for each kg of body weight) for 16 weeks. Sleep quality improved for those on the high-protein diet, but not for those on the normal-protein diet.

Sleep quality was assessed using the Pittsburgh Sleep Quality Index (PSQI) questionnaire.

The sources of protein were beef and pork, or soy and legume.

Higher protein intake has also been linked to promoting body fat loss, retention of lean body mass and improvements in blood pressure.

http://www.eurekalert.org/pub_releases/2016-03/pu-lww032416.php

Zhou, J., Kim, J. E., Armstrong, C. L., Chen, N., & Campbell, W. W. (2016). Higher-protein diets improve indexes of sleep in energy-restricted overweight and obese adults: results from 2 randomized controlled trials. The American Journal of Clinical Nutrition, 103(3), 766–774. http://doi.org/10.3945/ajcn.115.124669

A small, Israeli study involving 48 overweight and obese older adults with Type 2 diabetes (average age 59) has found that those who ate a large breakfast containing whey protein managed their diabetes better.

Participants in the study were randomly alloted to one of three diets that contained the same number of calories, and followed the pattern: large breakfast, medium-sized lunch and small dinner. They followed this diet for 23 months. The groups varied in the type of breakfast: primarily whey protein; other proteins such as eggs, soy and tuna; a meal high in carbohydrates or starch.

After 12 weeks, the group on whey protein lost the most weight: 7.6 kg (16.7 pounds), compared to 6.1 kg (13.4 pounds) for those on the other proteins, and 3.1 kg (6.8 pounds) for those in the carbohydrate group. Those on whey protein were also more satiated and less hungry throughout the day, with lower glucose spikes after meals compared to the other two diets, and their HbA1C also decreased more than with the other two diets.

http://www.eurekalert.org/pub_releases/2016-04/tes-lwp040116.php

Data from a five-year sleep study involving 161 Caucasian, 121 African American and 56 Chinese non-shift working women aged 48-58 has found that going to bed later, and having greater variability in bedtime, were associated with higher insulin resistance, and greater bedtime advance (going to bed earlier) was associated with higher body mass index (BMI).

Changes in bedtime, and later bedtimes, were partly due to shifts in bedtime at the weekend.

Diabetes risk increases in midlife women, and this finding suggests that irregular sleep schedules may be an important factor. Metabolic health was better in women who had more regular sleep schedules, including regular bedtimes across weekdays and weekends."

http://www.eurekalert.org/pub_releases/2016-02/aaos-sli020116.php

Taylor BJ, Matthews KA, Hasler BP, Roecklein KA, Kline CE, Buysse DJ, Kravitz HM, Tiani AG, Harlow SD, Hall MH. Bedtime variability and metabolic health in midlife women: the SWAN Sleep Study. SLEEP 2016;39(2):457–465.

Anecdotal and scientific evidence suggests curcumin, a compound found in turmeric, promotes health because it lowers inflammation. However, it is not absorbed well by the body. Most curcumin in food or supplements stays in the gastrointestinal tract, and any portion that's absorbed is metabolized quickly.

A new study thinks they've come up with a better and more effective way to deliver curcumin, and in so doing has demonstrated how it works. Curcumin powder was mixed with castor oil and polyethylene glycol, allowing it to dissolve and be more easily absorbed by the gut to enter the bloodstream and tissues.

When this was given to mice who had been injected with an extract that stimulates an immune reaction, a key protein that triggers an immune response was blocked. The mice given plain curcumin, on the other hand, showed the same protein actively triggering an immune response.

The emulsified curcumin also stopped recruitment of macrophages. Inflammation triggered by overactive macrophages has been linked to cardiovascular disease, disorders that accompany obesity, Crohn's disease, rheumatoid arthritis, inflammatory bowel disease, diabetes and lupus-related nephritis.

http://www.eurekalert.org/pub_releases/2014-11/osu-nra110614.php

One big issue for which there is as yet no clear answer, is the question of whether it's the intensity or the amount of exercise which is more important.

One study involving 300 obese adults aimed to test this in a 6-month trial comparing those who maintained their usual activity level, those who did a low amount (around 30 minutes) of low-intensity exercise, those who did a high amount (around an hour) of low-intensity exercise, and those who did around 40 minutes of high-intensity exercise. All had five exercise sessions every week.

After 24 weeks of this, all the exercise groups showed smaller mean waist circumference and greater mean weight loss, compared to the control group, but there was no difference between the exercise groups in these measures. However, only the high-high group had lower 2-hour glucose levels than the controls, and only the two groups who did a higher amount of exercise had better insulin sensitivity.

Ross R et al. Effects of exercise amount and intensity on abdominal obesity and glucose tolerance in obese adults: A randomized trial. Ann Intern Med 2015 Mar 3; 162:325. (http://dx.doi.org/10.7326/M14-1189)

Sleep apnea is common among overweight and obese individuals, and many people with prediabetes have untreated sleep apnea, although few of them are aware of it.

A study involving 39 middle-aged, overweight or obese volunteers with prediabetes and sleep apnea has found that those who received two weeks of CPAP treatment improved their blood sugar control and the ability of insulin to regulate their blood sugar, and also had lower blood pressure and lower levels of the stress hormone norepinephrine.

Two-thirds of the volunteers received continuous positive airway pressure (CPAP) for eight hours during the night; the other 13 received a placebo to be taken before bedtime. They were told the study would compare the two treatments. All participants slept in the sleep laboratory and were closely monitored.

http://www.eurekalert.org/pub_releases/2015-04/uocm-esa042715.php

Sushmita Pamidi, Kristen Wroblewski, Magdalena Stepien, Khalid Sharif-Sidi, Jennifer Kilkus, Harry Whitmore, and Esra Tasali "Eight Hours of Nightly Continuous Positive Airway Pressure Treatment of Obstructive Sleep Apnea Improves Glucose Metabolism in Patients with Prediabetes. A Randomized Controlled Trial", American Journal of Respiratory and Critical Care Medicine, Vol. 192, No. 1 (2015), pp. 96-105. doi: 10.1164/rccm.201408-1564OC

Public Health England states categorically for first time that excess weight is biggest risk factor for type 2 diabetes. Some 90% of people with the disease are overweight.

But note that abdominal fat is a better indicator of your chances of getting it than BMI. Men who measure more than 102cm (40 inches) around the middle are five times more likely to be diagnosed with type 2 diabetes than men with a smaller waist, while women who measure more than 88cm (35 inches) are three times more likely to be diagnosed than others.

http://www.theguardian.com/society/2014/jul/31/belly-abdominal-fat-type-2-diabetes

A Canadian study comparing neighborhoods that varied in “walkability” found that people living in neighborhoods with greater walkability had an average 13% lower likelihood of developing type 2 diabetes over 10 years, compared to those living in less walkable neighborhoods. However, walkability was only protective in those who were younger and middle aged; those who were age 65 or older saw no benefit from living in a walkable neighborhood.

Over the ten years of the study, the incidence of diabetes fell 7% in the most walkable neighborhoods, but rose 6% in the least walkable neighborhoods. Similarly, the incidence of excess weight (being overweight or obese) fell by 9% in the most walkable neighborhoods and rose 13% in the least walkable neighborhoods.

People who lived in the most walkable neighborhoods were three times more likely to walk or bicycle and half as likely to drive as a means of transportation.

The study was presented at the American Diabetes Association's 74th Scientific Session.

http://www.eurekalert.org/pub_releases/2014-06/ada-dn060214.php

A small 12-week clinical trial involving 52 overweight, middle-aged adults with high total and LDL cholesterol has found that those who ate a daily snack of almonds significantly improved a number of cardiovascular risk factors compared to those who ate a banana muffin.

Specifically, they decreased total cholesterol, LDL-cholesterol non-HDL-cholesterol and remnant lipoproteins, and reduced abdominal fat mass, waist circumference and leg fat mass (not total weight or fat mass — this is about distribution).

The muffin and the 1.5 oz (42g) of whole natural almonds had the same number of calories. Otherwise, the participants ate the same balanced diet. Participants followed each diet for six weeks, with a two-week “washout” period in between. Adherence to the diets was 85%.

http://www.eurekalert.org/pub_releases/2015-01/pn-nrs010615.php

Berryman CE, West SG, Fleming JA, Bordi PL, Kris-Etherton PM. Effects of Daily Almond Consumption on Cardiometabolic Risk and Abdominal Adiposity in Healthy Adults with Elevated LDL-Cholesterol: A Randomized Controlled Trial. Journal of the American Heart Association 2015; 4:e000993 DOI: 10.1161/JAHA.114.000993.

A small study involving 45 healthy, overweight or obese adults aged 21-70 has found that a diet including a daily Hass avocado was more effective than other cholesterol-reducing diets. Participants followed each of three diets for five weeks: one containing 24% fats and two containing 34% fats, one of which included an avocado and the other a comparable amount of high oleic acid oils (e.g. olive oil). There was a two-week break between each diet.

The avocado diet decreased bad cholesterol by 13.5 mg/dL, while LDL was decreased by 8.3 mg/dL on the moderate-fat diet and by 7.4 mg/dL on the low-fat diet.

http://www.eurekalert.org/pub_releases/2015-01/ps-aaa010715.php

Wang, L., Bordi, P. L., Fleming, J. A., Hill, A. M., & Kris Etherton, P. M. (2015). Effect of a Moderate Fat Diet With and Without Avocados on Lipoprotein Particle Number, Size and Subclasses in Overweight and Obese Adults: A Randomized, Controlled Trial. Journal of the American Heart Association, 4(1), e001355. http://doi.org/10.1161/JAHA.114.001355