For most people, sustaining fat loss is nearly impossible. They’re able to follow a diet for a few weeks and lose weight, but once they go back to their old eating habits, the fat comes back with a vengeance.
The reason is that when fat loss occurs, the human body ratchets down metabolic rate to prevent additional losses. A side effect is that people typically lose a large amount of muscle as well, which puts them at a major metabolic disadvantage.
It doesn’t have to be this way. There are a number of dietary and exercise strategies you can use to prevent rebound weight gain and help your body come out ahead metabolically.
#1: Weight Training Is The Most Important Exercise For Fat Loss
Most people know that weight training builds muscle. But did you know pumping iron is by far the most important exercise for reducing body fat because it gives you a metabolic advantage by maintaining lean muscle mass?
When people cut calories to lose weight, anywhere between 30 and 50 percent of the weight lost is from muscle mass. For example, when overweight women went on a low-calorie diet, they lost 7.8 kg of which 35 percent was lean mass. Only 5.1 kg of the weight lost was from body fat.
This is why the typical calorie-restricted diets almost always fail since they create a huge disadvantage in which the body burns substantially fewer calories. But it’s not the whole story
Recent evidence shows that for reasons that are not fully understood, many people become more sedentary after they lose weight. In one recent study, three groups of women went on a diet to lose 25 pounds, but one group did no exercise, one did aerobic exercise, and a third trained with weights.
The group that didn’t exercise lost lean muscle mass and they became more sedentary, decreasing the total energy burned over the course of the day by a humongous 259 calories. In contrast, the group that trained with weights increased the energy they burned daily by 63 calories daily, primarily due to non-exercise related activities.
Researchers believe that weight training allowed the women to improve how they felt about their bodies, which led them to be more active in spontaneous activity. Mobility and walking economy also improved. Among the women who did not exercise, movement economy worsened even though they now weighed less.
The bottom line: Training with weights is the magic bullet you’ve been waiting for when it comes to losing fat and keeping it off. Besides the physique-shaping curves you get from muscle, you’ll have a higher metabolic rate and better mobility so that you are more active throughout the day.
#2: Use Protein To Sustain Muscle Mass
Higher protein diets convey a metabolic advantage that makes fat loss easier. This is a scientific fact.
One reason for the benefit is that protein preserves lean muscle during fat loss in the same way as lifting weights. For example, when overweight women exercised in addition to eating a high-protein diet, they lost 9.8 kg, of which 96 percent was body fat, and only 4 percent (0.38 kg) was from lean tissue. Body fat percentage dropped by 6 percent. A group that ate a normal-protein (0.8 g/kg), low calorie diet lost a whopping 2.7 kg of muscle mass.
A similar outcome was seen with a 2013 study by Pasiakos in which lean, trained athletes who ate 1.6 g/kg of protein on a calorie-restricted diet were able to maintain lean mass, while losing 1.9 kg of body fat. By contrast, for subjects who got only 0.8 g/kg of protein, 58 percent of the weight lost was from lean muscle mass and they had the poorest fat loss results, losing 1.6 kg of body fat over the course of the study.
The bottom line: Increasing your protein intake is the best place to start if your goal is leanness because it protects muscle mass. Shoot for between 1.6 and 2.4 g/kg of bodyweight a day.
#3: Understand The Other Benefits Of A High Protein Intake
There are at least three other ways higher protein diets promote optimal body composition.
First, protein is filling. When people eat a greater percentage of their diet from protein, they feel more satisfied and eat fewer calories overall. One recent 12-week study found that by increasing protein intake from 15 to 30 percent of the diet, participants ate 441 fewer calories every day. By the end of the study they had lost 3.7 kg of body fat.
Second, it costs the body more calories to digest and process protein than carbs or fat, which is referred to as “thermogenesis.”
Quality is paramount here: A study showed that when subjects ate animal protein (meat) they had 17 percent higher increase in resting energy expenditure than a group who ate vegetable protein (beans and plant sources).
Third, protein helps manage blood sugar and insulin, decreasing cravings for sugar. High-protein diets tend to be naturally lower in carbs, and this combination leads to large, sustained reductions in insulin levels. Glucose tolerance also improves, which means that people have steady energy levels rather than “crashes” characterized by fatigue and sluggishness.
The bottom line: Reduced appetite, better insulin health, and a higher thermic effect of food make protein the most metabolically advantageous macronutrient.
#4: Eat High-Thermogenic Fats: Fish Oil, Nuts, & Olive Oil
Certain fats stimulate thermogenesis just as protein does, but these fats do it in a unique way. Studies show they enhance the activity of the uncoupling protein genes 1 and 3, which raises body temperature and leads to excess calories being burned.
Examples of the metabolic advantage you can get from eating certain fats include the following:
Overweight men ate foods with a high omega-3 fat content so that they increased their dietary intake from 0.43 grams a day to almost 3 grams a day. The results are impressive: The thermic effect increased by 51.3 percent and the men burned a whopping 920 calories during the 6-hour period after eating when metabolism was elevated.
In a crossover trial, thermogenesis was 28 percent higher after a meal of walnuts, and 23 percent higher after a meal that favored monounsaturated fats from olive oil compared to a saturated fat-rich dairy meal.
The bottom line: Healthy fats won’t make you fat but they can help you get lean.
#5: Eat Low Carb
The use of low-carb diets is one of the most hotly contested issues in nutrition today, but most experts agree that they are metabolically advantageous.
A couple of recent studies have found that lack of carbohydrates leads the body to use different energy pathways that are less metabolically efficient, so the body burns more calories.
If the diet is very low in carbs and high in fat, glucose and insulin will be much lower after eating and the body’s ability to burn fat will increase radically. In addition, glucose will need to be manufactured from protein in order to fuel the brain. Gluconeogenesis is a metabolically inefficient pathway that leads to a lot of calories being wasted in the process.
In one study, a very low carb diet (10 percent carbs, 60 percent fat, 30 percent protein) led to much higher energy expenditure of about 200 calories a day than a high-carb diet (40 percent carbs, 40 percent fat, 20 percent protein).
The bottom line: Low-carb diets are metabolically advantageous, though the benefits vary greatly based on ratio of fat, carbs, and protein, and duration of the diet.
#6: Do Sprints Or Interval-Style Training
Interval training that uses intense bursts of exercise interspersed with rest can provide a four-fold increase in metabolic rate in the post-workout recovery period.
Sprint training is a classical example of intervals, but you can get the benefit from high-intensity weight training, strongman exercises, or whatever exercise mode floats your boat. The key is to go hard and heavy during your workout, but keep it short and sweet—always less than 45 minutes including warm-ups.
For example, when trained men did a high-intensity weight training protocol, they burned an extra 452 calories during the 22-hour recovery period, whereas a group that did traditional weight training with full rest periods only increased metabolic rate by 98 calories.
The bottom line: If you need a little extra kick to your metabolism, do a few extra interval workouts because they will increase the calories you burn for up to 24 hours after your workout.