There is endless debate about the best way to lose weight. I think you already know that there is no answer to this question yet. I suspect that in the future we will be able to determine the “best” diet for you as an individual, and it will probably depend on your gut microbiome and genetics. While there is ongoing research on these topics, from a practical standpoint this we can’t use this info yet1There are companies selling genetic testing kits that claim to tell you this information, but I would be very skeptical at this point whether the information is valid.

 

Regardless of what type of diet you follow and what type of research breakthroughs we learn in the future, there will remain 2 truths about losing weight: 
1. To lose weight, you need a caloric deficit. 
2. To sustain weight loss, you have to change your diet permanently. 

In light of these 2 truths, I have built my nutrition recommendations on the following 2 concepts. 

  1. Because you need a caloric deficit to lose weight, you need to know your basal metabolic rate and you need to  accurately track calories. This ensures that early on, you can trouble-shoot your diet.
  2. In the long term, you will need to continue your diet even after you meet your weight goal. However, it is not realistic to keep up calorie counting forever. So in order to maintain weight loss, you need to make eating well your default behavior. That means you need to like your diet and your diet needs can’t be too complicated. 

Creating a Caloric Defecit

Every day in my clinic, I have patients tell me “I eat nothing yet I can’t lose weight”. While I believe you when you say you feel like you aren’t eating much at all, truth is that if you are restricting what you eat and you aren’t losing weight, then you aren’t restricting far enough below your basal metabolic rate to trigger weight loss.

 
The most accurate way (in a routine clinical setting) to determine your basal metabolic rate and caloric goal to lose weight is to use indirect calorimetry. However, this can be expensive and is not routinely available in most clinics. A far cheaper and quicker method is to use a predictive energy expenditure equation. Now, these equations are not perfect, but they get pretty darn close! The equation I use is Mifflin St. Jeor. In some people, it can overestimate the calorie goal by 6-10%. So I see it as a starting point. If you are not losing weight as predicted, you need to decrease the calorie and carb goal by up to 10%.

Counting calories

If you were opening a business you would track your expenses and revenue, right? You could just wing it and hope to make money, but you probably wouldn’t stay in business very long. 

Overhauling your lifestyle with the goal of permanent weight loss is very, very hard. If you want to succeed, you need a way of auditing your diet so that you can tell what is working. If you are hitting calorie goals and your weight is stagnant, then either you are not counting correctly or your metabolic rate is lower than predicted and you should cut your caloric intake another 10%

You will not be counting calories forever, you should do it until you reach your goal. 

Smartphones have made tracking food intake far easier than ever before, with apps having enormous databases of foods to make counting easier. Popular examples include myfitnesspalcarb manager, and myplate

 

How many meals should I eat?

Most people who have trouble with excess weight should be eating 2 meals per day, if they can do so comfortably and without having to resort to frequent snacking. Your lifestyle will dictate which 2 meals you eat. There are some people who will feel awful if they don’t eat 3 times per day. You know who you are. If you need to eat 3 meals, by all means, do so. 

You may be thinking, “but I was told I should eat 5 or 6 small meals a day”. Some nutrition and exercise professionals will still make this recommendation, with the idea that this helps optimize the resting metabolic rate. Studies have not backed up this theory (Reviewed here). In theory, “small frequent meals” would be fine if one could also achieve a caloric deficit. If you can eat this often and achieve a calorie deficit, then I do not have a problem with it. But… most people will fail miserably on such a diet because *what* you have to eat is boring and limited. Eat half a cucumber and a hard boiled egg? No thanks. 

As I mentioned above, most people will be able to lose more weight and keep it off if they can master reducing meal frequency to 2 meals per day, and minimize snacking in-between. If you need to eat 3 meals, that is OK too (it’s just a little trickier).

Is it OK to skip breakfast?

Yes. The evidence does not support the notion that you must eat breakfast. A meta-analysis of 13 clinical trials did not show any weight loss benefit to eating breakfast. Instead, people who were assigned to eat breakfast actually consumed about 260 more calories per day compared to subjects who were assigned to skip breakfast. 

Does it matter what time of day I eat?

LC Ruddick Collins, et al. The Big Breakfast Study: Chrono‐nutrition influence on energy expenditure and bodyweight. Nut Bull 2018

The short answer is that we don’t know. This has been talked about more over the past decade due to research in circadian rhythms. Nearly every gene in our body involved in metabolism is partially regulated by CLOCK genes, which are in turn regulated by light-dark cycles from our environment. We call this the circadian (24 hour) timing system. Here is a neat review article on circadian rhythms if you want to learn more. Some animal studies show that timing food consumption to the early part of the waking period can be associated with favorable metabolic parameters. However, I am not aware of any proof in humans that timing meals in accordance with this has a meaningful benefit to your health. And furthermore, modern human societies are not primed to eat the largest meal in the morning and smallest meal in the later afternoon/early evening. So even if there was proof that there was a benefit to shifting most food consumption to the morning, would this be implementable from a practical standpoint?

Your diet needs to be forever

Unfortunately, unless you can stick to your diet forever, regaining weight is expected. It appears there are 2 mechanisms at the heart of weight regain metabolic adaptation and neurohormonal changes to appetite. 

1. Metabolic adaptation
Weight loss is associated with a slowing of resting metabolic rate that is greater than what we expect changes in body composition. This phenomenon is called metabolic adaptation, and it acts to counter weight loss. Sadly, metabolic adaptation lasts for YEARS. This has been demonstrated in the famous “Biggest Loser” study, where researchers evaluated contestants from the biggest loser at the beginning of the competition, at the end of the 30 week competition, and 6 years after the competition. The contestants lost 127 +/- 55 pounds after 30 weeks. Their baseline resting metabolic rate was 2606 +/- 649 calories per day, which decreased to 1996 +/-358 calories at the end of the competition. 6 years later, despite the contestants gaining most of the weight back, the average resting metabolic rate did not significantly change (1903 +/- 466 calories). Overall, the average resting metabolic rate was about 500 calories per day lower than one would have predicted based off their body size and age.  

2. Neurohormonal changes to appetite control
Weight loss is associated with increased appetite, as well as changes in hormones that have been shown to regulate appetite. An often-cited study published in 2011 demonstrated changes in appetite-regulating hormone associated with weight loss. The patients had lower leptin, peptide YY, amylin, CCK (hormones that decrease appetite) and higher ghrelin, GIP, pancreatic polypeptide (hormones that increase appetite). Alarmingly, these changes persist for at least 5 years. 

It would be nice if you could just be aggressive in dieting, then coast once you hit your goal weight. But with metabolic adaptation, your slowed metabolic rate will cause you to regain the weight if you revert to a diet even somewhat close to what you were eating at baseline. And since your metabolic rate is now lower, losing the weight again will be even harder (you may have experienced that it gets harder to lose weight after you regain it)

Calorie Counting won't work forever

While calorie counting absolutely works in the short term, I don’t believe it is the path to long-term success because it is just too much work. As I mentioned earlier, most of the popular diets show similar efficacy with regard to weight loss, and they all generate a caloric deficit. I recommend calorie counting as it is the ultimate way to ensure a calorie deficit.  
However, is not realistic to think you can keep calorie counting indefinitely. Just like with any diet, there are times when motivation wanes and life gets in the way of the rules you set up for your diet. At some point, you have to develop habits that make eating the right thing the easiest, default choice. Habits such as planning meals out in advance and shopping for the meals over the weekend and keeping the house free of the foods you should be avoiding, for  couple of examples. 
The rationale and evidence behind habit-forming is something I am still learning about and that I have trouble explaining still. I’m reading Good Habits, Bad Habits by Wendy Wood and The Diet Trap Solution by Judith Beck. I will continue to expand this section as I learn more.