“I’ve reached my goal weight.” What needs protecting now

Believe it or not, reaching a goal weight can be an anticlimax. The number arrives and the structure that produced it - the plan, the appointments, the advice - stops with it. Almost none of that was aimed at what happens next.

What comes off with the weight

Weight loss isn’t selective. Any reduction in body weight, by any method, draws on both fat mass and lean mass (lean mass is mostly skeletal muscle).

The proportion varies. The main determinants are the rate of loss, protein intake during it, and whether the muscle was being loaded at the time. Faster loss and lower protein intake both increase the share that comes from lean tissue.

The result is a lighter body carrying less of the tissue that produces force. This is why some women report feeling weaker at their goal weight than they did carrying more, and why the number on the scale can improve while function doesn’t.

What’s worth protecting and why it matters now

Skeletal muscle, and the force it produces, is totally worth protecting. Muscle mass determines maximum force output, and force output is what carrying shopping, rising from a low chair and climbing stairs under load require. As lean mass falls, those tasks consume a higher percentage of available capacity. That’s what registers as things being harder.

What maintains it

Resistance exercise, two to three times a week. Muscle mass responds to mechanical loading and without a sufficient load stimulus it declines regardless of diet. Walking and other low-intensity activity don’t supply that stimulus, because the load sits well below the threshold that triggers adaptation.

The effective dose is modest - a small number of compound movements, loaded so the final repetitions approach “failure”, performed consistently.

Adequate protein is a requirement rather than an addition. It supplies the substrate; the loading supplies the signal.

What the evidence supports

Resistance exercise during and after weight loss preserves more lean mass than the same weight loss without it. This is pretty well evidenced.

What the evidence doesn’t support is your individual prediction. The magnitude and rate vary with baseline muscle mass, how quickly the weight came off, protein intake and consistency.

If the weight loss was medically supervised, maintenance is a conversation for the clinician who supervised it, which covers the exercise component only.

Strength changes precede visible ones

Improvements in force production are typically reported at four to six weeks and are largely neural - better recruitment of existing muscle rather than new tissue.

Measurable change in muscle mass generally occurs between eight and twelve weeks of consistent loading.

Function is a more useful measure than either the mirror or the scale - getting up from a chair without using your hands, and carrying a load upstairs, are both testable at home.

Where that leaves you

Weight loss and weight maintenance are different beasts and they need different interventions. The first is largely dietary. The second is largely mechanical.

Even one resistance session a week can start the intervention, so why not start now?