August 2024
Which Popular Diet Works Best?
An old study comparing the effects of the Atkins (A), Ornish (O), Weight Watchers (WW), and Zone (Z) diets didn’t settle the question but does make sense of the ultimate truth of any diet: any diet that reduces caloric intake long enough will help you lose weight and reduce cardiovascular risk factors (CRF).
We have covered many aspects and alternatives to weight management here, here, here, here, and here, but have done so with a humility that suggests the challenges inherent in years and tears of failed efforts.
A 1-year study of 160 subjects (ages 22-72) with BMIs averaging 35, having high blood sugar and high levels of CRF, enabled a hospital-based weight loss clinic to follow each group of participants dieting at “their own levels of dietary adherence” at various time points over the year. The A was low-carb; O was low-fat; WW reduced calories; and Z was a novel macronutrient balance (40% carbs, 30% fat, 30% protein) diet. Subjects participated in an intense support group for their diet for the first 2 months. They were weighed and blood tested at 2, 6, and 12 months without knowing when until 2 weeks beforehand. Multiple 3-day food records were assessed in order to gauge adherence.
Attrition is common in these kinds of studies: A lost 48%, O 50%, Z and WW lost 35% each. The most common reasons were that “the assigned diet was too hard to follow or not yielding enough weight loss”.
Adherence declined progressively over the year; mean daily caloric reductions were moderate: 138 for A, 251 for Z, 244 for WW, and 192 for O. Each group had modest success with ~25% losing 5% of initial weight and 10% losing 10% of initial weight. Those who adhered better and longer had the most success – duh! All but the A group lowered LDL levels, and only the O group did not raise HDL levels. Neither of the diets altered blood sugar and blood pressure. CRP levels declined in all groups but not significantly.
See ‘ultimate truth’ above.
JAMA 2005, Vol. 293
High Heels Could Be the Answer to Gait Problems
For years, many movement specialists have bemoaned the fashion trends that have reinforced wearing high heels (HH), particularly in women’s wear. Hence the movement toward no- or low-heel drop shoes. The very idea of intentionally wearing a shoe that raises the heel not only impairs posture by causing a forward lean and compensatory hyperextended lumbar spine but it also shortens the Achilles tendon, the thick tendon that attaches the calf muscle to the heel bone. But now a new study reports that doing so might, in fact, be the answer for non-athletes and athletes alike: it might increase gait efficiency.
Previous research has shown that those who habitually wear shoes with heels, by creating a shorter Achilles, improve the stored potential energy inherent in an elastic structure. Think of it this way: like a rubber band put under stretch, there is a greater ability to shorten. Our body prefers to minimize the effort to accomplish muscular tasks; if it can use stored energy, it saves muscular energy. Hence the study of the “influence of habitual high-heel use on users’ leg muscle-tendon structure and metabolism during walking in flat-soled footwear.”
It should be noted here that several studies and previous newsletters here, here, and here, have highlighted how, as we age, even among long-term joggers, we don’t use our calf muscles efficiently. So this study raises the possibility that we might have to rethink our gait training for the aging population.
They had 3 females and 5 males wear 2.5-3” HH for 14 weeks, regularly. Those who took >1500 steps/day had a 9% decrease in their net metabolic power demand while walking in flat shoes; even those walking <1000 steps/day got a 5.3% decrease. This was partially explained by shorter calf muscle fiber lengths and increased tendon stiffness. The savings in energy demand for walking in normal athletic shoes might, the researchers contend, make HH a viable way to help those with gait issues, or even athletes, improve speed efficiently.
Pradas, anyone?
JAP Mar. 2012, as reported in the Washington Post, Feb. 2024
Tid Bits
Those who cycle more tend to have a lower prevalence of knee pain, radiographic osteoarthritis (ROA), and symptomatic OA (SOA), according to self-administered questionnaire of 2607 participants in the Osteoarthritis Initiative study. For those who had bicycled at some point in their lives, the risk ratio for pain, ROA, and SOA were 0.83, 0.91, and 0.79, respectively, compared to those who were non-cyclers. MSSE Apr. 2024
Performing balance training in a fatigued state may not be the optimal timing when it comes to injury prevention. Three groups of young active subjects performed the same balance routine for 6 weeks, with one group serving as controls (BAL), one doing a high-intensity training (HIT) routine before (BAL-HIT) and the other after the HIT (HIT-BAL). All were tested on a variety of static balance tests and a jump test, fatigued and not fatigued. The BAL and BAL-HIT groups performed better when fatigued than did the HIT-BAL group, suggesting BAL training be done separately or before a training session. JSCR Feb. 2024
With protein supplementation and high protein dieting being all the rage, it makes sense that those who weight train (WT) to increase strength and/or hypertrophy would prioritize it. But this might be misplaced nutritional guidance. WT is an anaerobic activity that meets its endpoint at muscle fatigue. Protein repairs and builds the muscle but, as a recent study affirmed, central and peripheral fatigue is reached when carbohydrate within the muscle is depleted. Providing 85 g/hr of sucrose, vs a placebo, increased blood glucose during a fatiguing set of single-leg knee extensions and increased the duration of the lifting task, maintained maximal torque, and sustained a higher percent of neuromuscular activation. That is, carb “intake mitigates neuromuscular fatigue at both the central and peripheral levels.” MSSE Apr. 2024
