Exercise Versus Dieting: Preventing weight gain

July 4, 2016

Conventional wisdom says that dieting is essential to weight loss and that exercise alone is generally insufficient for weight loss.

However, a new study looked at a related topic – preventing weight gain. This study compared three groups of obesity-prone rats. The control group was sedentary. The second group of rats exercised regularly in running wheels. The third group of rats was sedentary and on a calorie-restricted diet. All three groups ate the same kibbles though daily servings for the calorie-restricted group were 20% less than that for the group of runners.

Unsurprisingly, the control group turned out to be obese at the end of the study. The other two groups staved off obesity. However, the runners were metabolically healthier in terms of insulin sensitivity, cholesterol, burning more fat and they also seemed to have more metabolic activity within their brown fat. Interestingly, gut microbes in the runners were different from gut microbes in the calorie-restricted group, so exercise had a probiotic effect even though all groups had been fed the same kibbles.

This study suggests that exercise alone can deliver results that are far superior to dieting alone – at least for rats trying to avoid obesity. It seems reasonable to assume that this would be true for humans too, though it is obviously important to focus on both exercise and calorie intake while eating healthy food.

How Walking in Nature Helps the Brain and Combats Stress

June 21, 2016


Walking is tied to a number of  health benefits and should (almost) always be encouraged. That is why we created a pedometer app to track steps. However, anecdotally, many of us would agree that walking in a natural environment is generally a more pleasant experience than other walking. From my own experience in walking in cities and towns across four continents and natural environments across five continents, I can relate to Henry David Thoreau who said “I think that I cannot preserve my health and spirits, unless I spend four hours a day at least – and it is commonly more than that – sauntering through the woods and over the hills and fields,  absolutely free from all worldly engagements.” even though I myself don’t walk four hours a day in any environment, let alone walk in nature for four hours.

Given anecdotal experience with walking in nature, it is interesting to see that medical science can now use data to explain the neurological mechanisms of how walking in nature helps the brain. A Stanford study establishes that cerebral blood flow and neural activity in the subgenual prefrontal cortex (sgPFC) is decreased for nature walkers and not for urban walkers. Self-reporting from the walkers also showed that nature walkers ruminated less. I first heard about this study from a column that explains the Stanford study for a wider audience

The sgPFC (or Brodmann Area 25, BA25) plays a major role in depression and decreased neural activity in this area can help prevent depression and combat stress. Since walking in nature helps the brain (specifically the BA25 region) and decreased rumination/brooding helps reduce stress, the results of the Stanford study strongly suggest that walking in nature can change the brain in ways that help mental health, improve mood and reduce the chances of depression.

Clearly, walking in nature is not a viable option for all people in all circumstances. Health conditions, weather conditions or concerns about some wild animals, criminal humans etc. may dissuade some people from walking in nature. However, for those who enjoy walking in nature and for those who’d like to consider it, studies seem to establish that walking in nature can impact the subgenual prefrontal cortex in ways that are good for the brain.



My work with Satya Nadella, my thoughts on Microsoft’s new CEO and his Oscar Wilde quote

February 28, 2014

I’ve spoken with Bill Gates in person and I’ve spoken with Steve Jobs on the phone. Both were relatively brief conversations. However, among major US company CEOs, Satya Nadella is the only guy who has come to my office to speak with me.

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Was Apple right to purge AppGratis from the App Store ?

April 9, 2013

The Wall Street Journal published a report on “Apple Kicks AppGratis Out of the Store” and AppGratis formally responded to the WSJ story today. It is a detailed response that adds a lot to the conversation around app store curation, but it doesn’t address a couple of key points from the WSJ report.

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The App Store Long Tail Myth

August 1, 2012

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Steve Jobs, 1955 – 2011

October 5, 2011

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