Healthy Food & Healthy Living by Dr. Ayala

This is how weight is gained

Although people blame vacations, holiday meals and older age, weight is actually gained slowly and steadily over a lifetime. Much like you don‘t notice the slow bodily transformation from teenager to young adult to middle aged, as there’s no clear demarcation, weight stealthily adds up unnoticed – until it is.

More than 40 percent of the adult US population is obese, and since obesity is a risk factor for a multitude of chronic diseases – including stroke, heart disease, diabetes and several cancers – understanding how weight is gained can help mitigate this raging epidemic.

A new study in the Journal of Obesity looks at weight gain over a decade of almost 14,000 statistically representative Americans. The results are concerning.

Over 10 years more than half of the people followed in the study gained 5 percent or more body weight, more than a third gained 10 percent body weight or more, and a fifth added 20 percent.

Weight gain over the decades

The study shows an inverse relationship between age and weight gain. The greatest weight is gained by young people – between 20s and 30s – in which an average of almost 18 pounds of weight is added on.

Between 30s and 40s weight gain averages about 14 pounds. It slows further down to about 10 pounds for the 5th decade of life, and to 5 pounds for the sixth.

This pattern adds up to 47 pounds over four decades.

People usually think that older age and slower metabolism leads to the accurate observational finding that the older the population the greater the obesity incidence. This is not the case according to these findings. 

In fact, people gain the most weight when they’re young, but despite gaining 18 pounds by the mid 30s many young people are not obese – it takes further weight gain to push you into the obese category.

Obesity rises with age because the older you are the more years you have to steadily gain weight, a process that actually starts early on.

Why would weight gain slow down with age? One reason is that the bigger the body, the more energy it needs, so if you gain significant weight in your 20s and 30s, if you continue eating the same amounts you’ll gain less weight in subsequent years. 

Habits over time

We’ll all age with time – it’s inevitable. But we don’t have to get fatter over the decades – that’s avoidable with better eating and exercise habits.

It's mostly eating habits – lifelong habits – that determine weight gain trajectory.

Studies in overfeeding, in which people were fed 1000 excess calories daily for three weeks led to more than 4.5 pounds gained. But the excess weight was lost within 6 weeks after the overfeeding experiment ended. Extend that to 100 days – which is what was done in another study – and weight gain was on average 18 pounds, and although much of the weight was lost when the experiment ended, 3 extra pounds lingered, and the participants continued to gain weight over the years. 

It's what you do day in and day out that matters the most.

It’s wise to take inventory of your eating habits early on (and it's never too late), add highly nutritious healthy foods such as fruits, vegetables and whole grains, and cut out unhealthy, seductive calorie bombs, such as highly processed foods, foods with lots of added sugar, and sugary drinks.

Dr. Ayala

Is our love affair with protein healthy?

Americans are obsessed with protein. Fat and carbs have been vilified – for unjustified reasons for the most part; there’s nothing inherently wrong with these two macronutrients, even though some fats and refined carbs are foods to limit.

Protein on the other hand has gained a health halo, as many people think that eating more of it will build muscle and help them eat less – hence the popularity of protein shakes and powders.

The body requires protein for its upkeep – from 10-35 percent of daily calories should come from protein, or about 0.8 gram of protein per kg of weight. Athletes, children, pregnant and breastfeeding women, and older adults need more protein than the average adult. 

Protein malnutrition plagued the world in the past, and is still an issue in some parts of the world. The American diet, however, has abundant sources of protein from plants (nuts, seeds, legumes, soy, grains etc.) and from animal sources (meat, fish, seafood, cheese, eggs etc.). Pair this abundance with our appetite for protein, which drives people to pack a protein bar and jerky in their bag just in case, and most Americans get twice as much as they need.

Too much of a good thing?

What happens with excessive protein? 

It does not, as some believe, turn into extra muscle. 

If that extra protein replaces other food (perceived as having a macronutrient that’s out of favor, such as carbs), and caloric intake is adequate, you might be missing out on other nutrients that come from foods not as famous for their protein content. Focusing on protein may turn you away from vegetables, many of which also contain protein, among their very many other important micronutrients: 1 cup of broccoli has 3 grams of protein, a third of its dry weight is in fact protein. 

If that extra protein makes you exceed your caloric expenditure, its energy will be stored as fat, and you’ll gain weight. 

Excess protein is metabolized, its extra energy is stored as fat, other components are broken down and excreted. Protein's amino acids break down into nitrogen, which is excreted through the urine mainly as urea.

A high protein diet may put extra strain on the kidneys.  This is especially worrisome if there’s an underlying kidney disorder – which is not uncommon, as up to a third of Americans are at risk of kidney disease due to conditions such as diabetes and hypertension. 

A new study in Frontiers in Ecology and the Environment looks at how our excessive protein intake affects the environment, especially our waterways.

As mentioned above, the more protein you take in, the more nitrogen you excrete. Multiply that by the US population, and this makes for a significant flow of nitrogen to our waterways. Sewage actually makes 15 percent of the total nitrogen flux from land to ocean in North America. The technology that removes most nitrogen from sewage exists, but it’s expensive, and used on only 1 percent of sewage.

This human contribution of nitrogen to rivers, oceans and lakes results in excessive nutrients in the water, which lead to plant material overgrowth, toxic algal blooms, and hypoxic dead zones. It can make water unsafe to drink. “For most healthy individuals, greater protein consumption has negligible positive health benefits but is potentially deleterious to the environment,” the authors write.

The researchers analysis suggests that if Americans ate the recommended protein amounts it would reduce nitrogen losses into waterways by 12 percent. 

If you also take into account the production of our excess protein food – 60 percent of US protein intake is from animal sources – eating the recommended protein allotment will improve environmental stability much further, as the meat industry is a major contributor to greenhouse gasses and nutrient runoff.

Thinking of food as nutrients isn’t serving our health, as protein isn’t in and of itself better than fat or carbs – they’re all necessary, and can come from healthy – or less healthy – sources. Our focus should be on healthy foods and portion control. If, to increase protein intake, you replace a sugary drink with nuts or legumes this is an improvement. But opting for whey and casein protein powders and processed meat instead of whole foods is clearly a nutrition downgrade, regardless of the macronutrients involved. And this protein-overload trend has environmental costs, too.

Dr. Ayala