The first few weeks of a diet are magical for most. This period is typically characterized by rapid weight loss and jokes about how the fat is practically melting off. However, the majority of initial weight loss in those with significant weight to lose is not body fat. And this rapid change on the scale can lead to unrealistic expectations about rate of weight loss and an end of diet weight, which increases the psychological challenge of facing the truth about a healthy and sustainable goal and approach to weight loss (and eventually weight maintenance).

Understanding why the scale moves so quickly at first is crucial for a better understanding and expectation of total weight loss and physique changes along the way. This rate of change will not last, or, rather, it should not last because losing weight too quickly increases your risk of muscle loss and likelihood of rapid weight regain and binge behaviors post-diet.

Below are three major contributors to initial weight loss that you need to be aware of to best set and manage your weight loss expectations and end of diet weight – read on to make sure you’re setting yourself up for success!

1. DECREASED INTESTINAL BULK

Depending on what you eat and drink, it may take 24 – 72 hours for your last meal to be digested, absorbed, and removed from your body. This means that for a prolonged period, you have a significant amount of food sitting in your digestive tract. When you begin eating less, this timeline doesn’t change, however, you now have less food in your digestive tract at a time, which impacts the number on the scale.

2. YOU’RE STORING FEWER CARBOHYDRATES

Carbohydrates are stored in your liver and muscles as glycogen. The average person may store at least 400 grams of carbohydrates between the two storage locations at a time. However, when you begin eating fewer calories, which typically means you begin eating fewer carbohydrates (not in all cases), you’re left with slightly depleted muscle glycogen stores, thus, you’re carrying around less weight, so to speak, at any given time.

3. YOU’RE STORING LESS WATER

One gram of carbohydrate carries three grams of water into the liver or muscles when being stored as glycogen. When you begin eating fewer carbohydrates, you lose water in a 3:1 ratio for each gram of carbohydrate; thus, you now have less glycogen AND less water stored in your body at any given time, which leads to a lower number on the scale.

ORIGIN AND RATE OF WEIGHT LOSS CHANGES THROUGHOUT YOUR DIET

Of course, if you’re eating fewer calories than you need and exercising consistently, you’re likely losing body fat early on in your diet, too. However, it’s important to know that the change in the number on the scale week after week reflects a change in intestinal bulk, carbohydrate stores, water stores, and body fat loss.

As you progress throughout your diet, the amount of this total change that is related to body fat increases as your food intake stays steady for a period of time. However, the total change as you progress lessens, meaning the rate of body fat loss may not change much.

EXAMPLE RAT AND ORIGIN OF WEIGHT LOSS:

Weeks 1 – 3 Average Weekly Change: 5 pounds/week

Intestinal Bulk: 25%
Glycogen Content: 25%
Water Content: 25%
Body Fat: 25%
Total Loss of Body Fat: 1.25 pounds/week

Weeks 4 – 5 Average Weekly Change: 2 pounds/week

Intestinal Bulk: 10%
Glycogen Content: 10%
Water Content: 10%
Body Fat: 70%
Total Loss of Body Fat: 1.4 pounds/week

GOAL RATE OF WEIGHT LOSS

To maximize muscle maintenance and energy levels and to minimize hunger throughout your diet, you should aim for a rate of weight loss of 0.5 – 1.0 percent of your body weight each week.

WEIGHT(LBS.)

0.5% OF BODY WEIGHT

1.0% OF BODY WEIGHT

120

0.60

1.20

130

0.65

1.30

140

0.70

1.40

150

0.75

1.50

160

0.80

1.60

170

0.85

1.70

180

0.90

1.80

190

0.95

1.90

200

1.00

2.00

210

1.05

2.10

220

1.10

2.20

230

1.15

2.30

240

1.20

2.40

250

1.25

2.50

260

1.30

2.60

If you experience rapid weight loss the first two weeks, that’s okay. It’s to be expected, especially if you have more than 10 percent of your body weight to lose. Before making any further adjustments to your nutrition and exercise plan, wait until your rate of weight loss stalls and drops below 0.5 percent of your body weight per week before making any further adjustments. Then, you can reduce your caloric intake by 10 – 15 percent to recreate an appropriate calorie deficit to drive weight loss.

For more information on how many calories you should reduce to drive weight loss click here.