Weight loss can be tied to when, not just what, you eat
(CNN) - By Lisa Drayer, CNN , May 19, 2017 If you are trying to lose weight and otherwise
improve your health, you may already be mindful about what you eat during the
day.
You might skip breakfast. At lunch, you may
opt for a salad with lots of veggies, no croutons and low-fat dressing -- on
the side, of course.
Then, three o'clock hits.
You're incredibly hungry and craving candy,
sweets or chips. You finally cave, eating a candy bar or other treat.
By 6 p.m., you're tearing the kitchen apart,
snacking on anything you see
Despite your best efforts at cutting carbs at
meals, you give in to a large helping of pasta or pizza. And then another. But
you're still not satisfied. Dessert is calling, and you want something sweet,
again. A scoop or two of ice cream satisfies you for the moment, but you
continue to graze into the night until finally, you're so tired, you crash into
bed.
So what is the cause of all of this diet drama
that keeps occurring, almost according to schedule?
"I started noticing a common pattern
where my patients were so good with restricting their calories during the day,
but in the late afternoon and evening, they fell apart," said Tamara Duker
Freuman, a nutritionist who has helped hundreds of people lose weight over the
past decade on a meal-timing based plan she describes as the
"circadian-synced diet."
"It was the ongoing grazing into the
night. ... That's what kept undermining them. They often thought they were
binge eaters ... but in reality, they were just really hungry.
"If they just ate a little more at
breakfast and lunch, if they just added a few hundred extra calories in the
morning, they would get their eating under control and lose weight," she
said.
Despite your best efforts at cutting carbs at
meals, you give in to a large helping of pasta or pizza. And then another. But
you're still not satisfied. Dessert is calling, and you want something sweet,
again. A scoop or two of ice cream satisfies you for the moment, but you
continue to graze into the night until finally, you're so tired, you crash into
bed.
So what is the cause of all of this diet drama
that keeps occurring, almost according to schedule?
"I started noticing a common pattern
where my patients were so good with restricting their calories during the day,
but in the late afternoon and evening, they fell apart," said Tamara Duker
Freuman, a nutritionist who has helped hundreds of people lose weight over the
past decade on a meal-timing based plan she describes as the
"circadian-synced diet."
"It was the ongoing grazing into the
night. ... That's what kept undermining them. They often thought they were
binge eaters ... but in reality, they were just really hungry.
"If they just ate a little more at
breakfast and lunch, if they just added a few hundred extra calories in the
morning, they would get their eating under control and lose weight," she
said.
At the end of the 20-week study period, the late eaters lost
less weight compared with the earlier eaters (17 vs. 22 pounds
on average, respectively) and lost their weight more slowly, despite the fact
that both groups ate approximately 1,400 calories per day and consumed similar
amounts of fat, protein and carbohydrates.
Another study followed two groups of overweight women
with metabolic syndrome on identical 1,400-calorie weight loss diets for 12
weeks. The only difference between the groups was that their calories were
distributed differently throughout the day: Both groups consumed 500 calories
at lunch, but one group consumed 700 calories for breakfast and a 200-calorie
dinner (the "big breakfast" group), while the other group ate 200 calories
at breakfast and 700 calories at dinner (the "big dinner" group).
The nutrient content of the meals was exactly
the same for both groups, the only difference being that the breakfast and
dinner meals were swapped. After 12 weeks, the big breakfast group lost about
2½ times more weight than big dinner group (8.7 pounds for big breakfast group
vs. 3.6 pounds for big dinner group) and lost over 4 more inches around their
waist.
The big breakfast group experienced a 33% drop
in triglyceride levels -- a marker associated with heart disease risk -- while
the group that ate the higher-calorie dinner experienced a 14.6% increase. The
bigger breakfast group also experienced greater reductions in fasting glucose,
insulin and insulin resistance scores, all of which indicate decreased risk for
type 2 diabetes, according to the study's authors.
So front-loading calories and carbohydrates is
not only favorable in terms of weight loss, it had beneficial effects on other
indicators of overall health, including decreased risk for type 2 diabetes and
cardiovascular disease.
That second study "opened my eyes,"
Freuman said. "It wasn't just that people were less hungry and eating less
at night, but it pointed to the fact that there might be some sort of
underlying metabolic magic going on, where the timing of calories and carbs
mattered more than the total amount of calories and carbs eaten in a day. It
helped me understand what I was intuitively seeing in my patients."
Circadian rhythms: the
'metabolic magic'
More and more research is suggesting that when
you eat may be just as important as what you eat. And it is very closely tied
to the complex science of circadian rhythms.
According to the National Institute of General
Medical Sciences, circadian rhythms are physical, mental and behavioral
changes that follow a roughly 24-hour cycle, responding primarily to light and
darkness in an organism's environment.
Circadian rhythms
are driven by biological clocks inside our bodies. The brain has a master
biological clock, influenced mainly by light, which tells
"peripheral" clocks in the muscles and organs what time of day it is.
Because of these clocks, many of the metabolic processes that take place inside
us operate at different rates over the course of a 24-hour period.
Because of circadian rhythms, there are
variations in certain hormone levels, enzyme levels and glucose transporters at
different parts of the day, which differentially affect how calories,
carbohydrates and fat are metabolized," said Freuman, who presented case
studies of patients who improved their weight and health by eating in sync with
circadian rhythms at the New York State Academy of Nutrition and Dietetics
annual meeting in May 2016.
Circadian rhythms can help explain why eating
late at night increases the likelihood of weight gain and decreases the rate at
which we lose weight, compared with eating earlier in the day.
For example, research suggests that the
calories we burn from digesting, absorbing and metabolizing the nutrients in
the food we eat -- known as diet-induced thermogenesis -- is influenced by our
circadian system and is lower at 8 p.m. than 8 a.m., according to Frank A.J.L.
Scheer, director of the Medical Chronobiology Program in the Division of Sleep
and Circadian Disorders at Brigham and Women's Hospital in Boston.
Other metabolic processes involving insulin
sensitivity and fat storage also operate according to circadian rhythms and can
greatly influence the likelihood of weight gain or weight loss at different
times of the day.
"These different metabolic processes ebb
and flow at different times of the day, and they play a role in how your body
metabolizes food energy, which ultimately affects your weight, cholesterol
levels and blood sugar control -- and so it has tremendous implications for
what is considered optimal times for eating," Freuman said.
Breakfast-skippers
beware
Circadian rhythms may help explain why
breakfast skipping is associated with increased risk of weight gain, even among
those who consume comparable amounts of calories in a day.
"The link between breakfast skipping and
obesity had once been thought to be due to overcompensation of calories at
subsequent meals due to excess hunger ... but the research does not
consistently show differences in total energy intake among
breakfast-skippers," Freuman said.
"Something else about skipping breakfast
-- aside from potentially eating more calories later in the day -- must explain
the greater risk of weight gain among breakfast skippers," she said. A
more likely answer: Eating more calories in the later part of the day is out of
sync with metabolic circadian rhythms.
"We get less metabolically robust as we
age," she explained. "So even if you've gotten away with skipping
breakfast and eating out of sync in your 20s or 30s, it may eventually catch up
with you."
Night shift workers can also benefit from
eating in sync with their circadian rhythms. They may modify meal timing to
sync up with metabolic circadian rhythms by eating breakfast at the end of
their workday, at 7 or 8 a.m., and then eating their heaviest meal when they
wake up, about 3 or 4 p.m.
Freuman discourages her night shift patients
from eating during the night. "We don't want them eating many calories, so
we'll have them sip on tea or have a Thermos of miso soup or, if need be,
something small like an apple in order to minimize overnight calories.
"Your metabolism is working in a certain
way, whether you are awake or asleep -- so even if you are awake during most of
the night, you still want to be eating most of your calories during daylight.
Sleep has little to do with it," Freuman said.
Tips for eating in
sync with circadian rhythms
So how do we eat in sync with our circadian
rhythms? They key is to front-load your calories and carbs. Freuman suggests
the following, which she advises to her patients:
1. Don't skip breakfast
Ideally, breakfast should be satiating enough
to preclude the need for a midmorning snack, and it should have a minimum of
300 calories, according to Freuman. It should always include high-fiber
carbohydrates, which are more slowly digested than refined carbs, and it should
include protein, which helps keep hunger in check.
Good breakfasts include a cup of cooked
oatmeal with low-fat milk and a small handful of nuts, two slices of Ezekiel or
whole-grain bread with mashed avocado and sliced tomato, or a two-egg omelet
with veggies, fruit and a slice of whole-wheat toast.
If you are not hungry when you wake up, you
can defer breakfast for a few hours -- but it should not be skipped, according
to Freuman.
2. Have the "blue plate special" for
lunch
"Lunch should be like that blue plate
special ... the main meal of the day," Freuman said.
For a simple lunch strategy, Freuman suggests
filling half of your plate with non-starchy vegetables and then dividing the
second half into protein (like grilled fish or chicken) and slowly digested
high-fiber carbohydrates (like beans or quinoa). "A salad with grilled
chicken is fine, but try adding a baked sweet potato, a heaping scoop of
chickpeas or even a thick, hearty lentil soup," she said.
If you prefer a sandwich for lunch, pair it
with fiber-rich vegetables. "A turkey sandwich is part of a good lunch,
but it's not a whole lunch." Try adding butternut squash soup or carrots
with hummus.
Other good lunches that Freuman recommends
include baked salmon with lentils and cooked green veggies or a Mexican quinoa
bowl with quinoa, black beans, chicken, avocado and salsa, along with a pile of
greens.
The easiest way to plan for lunch may be to
use last night's leftovers. "I cook dinner at home and bring in my
leftovers for lunch the next day. When I get home from work, I'm not tearing
the house apart."
3. Pack a snack
An afternoon snack may be necessary if lunch
and dinner are more than five hours apart. However, it should be no more than
200 calories, and it should be high in protein and fiber. "This will
prevent you from arriving at dinner feeling 'starving,' " Freuman said.
Snacks that will satisfy include an apple with
a tablespoon of peanut butter, grape tomatoes with string cheese, a hard-boiled
egg or plain Greek yogurt with fruit.
4. Go low-carb for dinner
Dinner should be light and low in
carbohydrates. "The more you can go low-carb for dinner, the more it will
mitigate the effects of distorted calories at night," Freuman said.
Dinners might include fish and a cooked
vegetable, lettuce-wrapped tacos or a turkey burger (minus the bun) and a salad
with light dressing.
"I'll make turkey meatballs for my kids,
and I'll give them pasta too, but I'll have mine on a bed of spinach -- and the
next day, I'll bring the pasta for lunch."
And when dining out, Freuman suggests ordering
two appetizers, like a salad and a shrimp cocktail or grilled calamari.
